Size and Shape

Children are distinct from adults in a variety of physical, physiologic, and psychological ways. The most obvious difference is size. During development, children may grow from the average 7-lb (3.18-kg) baby to a 140-lb (63.5-kg) adolescent, a 20-fold difference. Accordingly, medications and fluids must be calculated on an individual basis, based on the weight of the child. Table 99-1 lists average weights for age.

TABLE 99-1 Average Weight for Age

From U.S. Centers for Disease Control and Prevention National Center for Health Statistics (http://www.cdc.gov/nchs/).

This variation in size also influences a child’s risk of developing serious complications from envenomations. Many snakes, spiders, scorpions, and poisonous marine animals deliver the same dose of venom regardless of the size of the victim. Children often experience greater toxicity because of the increased dose of venom per kilogram of weight.

Children are not only smaller than adults, they also have a larger surface-area-to-mass ratio. For example, a 7-lb (3.18-kg) infant has 2.5 times more body surface area per unit weight than a 140-lb (63.5-kg) adult. Not only is the surface area of the young child’s body larger, the head, which is the part of the body most often left exposed, also takes up a larger proportion of the body (Figure 99-1). As a result, children experience greater exposure to environmental factors, such as cold, heat, and solar radiation. They are also more likely to suffer toxic effects from topical agents, such as medications.

FIGURE 99-1 Body proportions.

Musculoskeletal System

The musculoskeletal system in children differs from that in adults in several important ways. A child nearly doubles in height between birth and 2 years, and again between 2 and 18 years. In some respects, this rapid growth makes a child’s bones much more forgiving. Because of the active osteogenic potential of the periosteum, nonunion or permanent angulation deformities at the metaphysis are unusual in children. For the same reason, fractures in the pediatric population heal quite rapidly. For example, a fractured femur typically heals in 3 weeks in a newborn, compared with 20 weeks in a 20-year-old. The strong, pliable periosteum also allows for greenstick and buckle fractures, which are not seen in the adult population. These fractures with their intact periosteum are quite stable, with little swelling or crepitus. If nondisplaced, they are often incorrectly dismissed as sprains.

Another key difference between the musculoskeletal systems of children and adults is that children have an open growth plate, or physis, at the ends of long bones. The physis connects the metaphysis to the epiphysis and consists of soft cartilaginous cells that have the consistency of rubber and act as shock absorbers (Figure 99-2). They protect the joint surfaces from suffering the grossly comminuted fractures seen in adults. However, because the growth plate is more vulnerable to injury than are the strong ligaments or capsular tissues that attach to the epiphysis, a true sprain in a child is rare. Any significant juxta-articular tenderness in a child should be assumed to be a growth plate injury and immobilized accordingly. Such an injury is most common at the ankle (lateral malleolus), knee (distal femur), and wrist (distal radius). Physeal fractures have been classified into five Salter–Harris groups (see Figure 99-2). Salter–Harris I and II fractures generally heal without complications. Salter–Harris III and IV fractures often require open reduction of displaced fractures to realign the joint and growth plates and to permit normal growth. A Salter–Harris V fracture has a poor prognosis; impaction and crushing of some or all of the growth plate may result in a bony bridge that inhibits further growth or causes unequal, angulated growth. Consequently, any significant injury, especially if it involves the growth plate, requires full evaluation in a medical facility.

FIGURE 99-2 Salter–Harris classification of physeal fractures (I to V).

Cardiovascular and Respiratory Systems

Basic physiologic parameters change greatly during the transitions from infancy to childhood to adulthood. Recognizing these differences is important to avoid unnecessary and potentially harmful interventions in healthy children, and to intervene aggressively when abnormal vital signs are truly present. For example, a blood pressure of 70/35 mm Hg, pulse rate of 160 beats/min, and respiratory rate of 50 breaths/min are considered ominous vital signs for an adult. However, these vital signs are normal in a 2-month-old infant. Although blood pressure readings may not be available in a wilderness setting, it is possible to assess the general appearance, work of breathing, respiratory rate, pulse, and peripheral circulation of an ill child. These observations can accurately predict how sick a child is. In general, infants and children have higher respiratory and heart rates and lower blood pressure than do adults. The normal values for various age groups are presented in Table 99-2. It is important to note that children can often maintain normal blood pressure in the face of significant fluid or blood losses. Once blood pressure drops, however, children can deteriorate very rapidly. Therefore, prompt and aggressive fluid resuscitation is essential when other signs of dehydration or volume loss (e.g., tachycardia, increased capillary refill time, cool extremities) are present.

TABLE 99-2 Age-Specific Resting Heart Rate and Respiratory Rate*

* Mean rate, ± 2 SD.

Thermoregulation

Because environmental extremes are often encountered when traveling in wilderness areas, it is important to recognize that thermoregulation is less efficient in children than in adults. A number of physiologic and morphologic differences make children more susceptible than adults to heat illness. During exercise, children generate more metabolic heat per unit mass than do adults. Children also have lower cardiac output at a given metabolic rate, resulting in lower capacity to convey heat from the body core to the periphery. Because they have a larger surface area–to-mass ratio, children also gain heat more rapidly from the environment than do adults when ambient temperature exceeds skin temperature. In hot environments, cooling from conduction, convection, and radiation ceases to be effective, leaving evaporation (sweating) as the only effective means of heat dissipation. Unfortunately, children have a lower capacity for evaporative cooling, presumably because of decreased sweat volume, regional differences in sweat patterns, and a higher sweat point (the rectal temperature when sweating starts).⁴² Finally, children acclimatize to hot environments at a slower rate than do adults.

Children are also at greater risk for hypothermia. Their larger surface area–to-mass ratio causes them to cool more rapidly than adults in cold environments. Children also have less subcutaneous fat and, therefore, less body insulation. Infants, in particular, have an inefficient shivering mechanism. This makes them particularly vulnerable to cold environments because shivering is the primary means of generating extra heat when humans are cold.⁴ In general, humans are poorly adapted for cold environments and must rely on adaptive behavioral responses, such as seeking shelter and dressing appropriately, to maintain body heat. Infants and young children are not capable of these responses and must rely on caregivers to provide shelter and appropriate clothing.

Immunology and Infections

Children experience a greater number of infections than do adults. The average 1-year-old suffers six to eight infections per year, whereas the average adult has only three to four infections per year. Infections in children also tend to be more severe. The younger the child, the more likely it is that a given infection represents a first exposure to a pathogen. A first-exposure infection is more likely to cause fever and produce severe symptoms than reexposure, in which the infection is attenuated by antibodies produced from the first exposure. Young children are also less likely to have cross-reacting antibodies from previous infections with antigenically related organisms. When present, cross-reacting antibodies serve to attenuate the immunologic response to an infection, thereby mitigating symptom severity.

Many common respiratory or viral infections tend to produce more severe symptoms in children because of anatomic differences. The pediatric bronchioles, eustachian tubes, and larynx are narrower and, therefore, more easily obstructed by edema and mucus. This obstruction worsens symptoms, prolongs clearance of infection, and increases risk for secondary infection. Pertussis (whooping cough) is a classic example of the difference in severity of infection between children and adults. Nearly 20% of infants with pertussis have severe complications, such as apnea, pneumonia, seizures, or encephalopathy. In contrast, adult pertussis, although a common cause of chronic cough, is generally indistinguishable from a common cold.

Trauma

Blunt trauma is the leading cause of morbidity and mortality in children ages 1 to 18 years. Closed head injuries are responsible for 80% of pediatric trauma deaths.⁴⁴ Although pedestrian and motor vehicle accidents are the source of many of these injuries, falls and drowning are close behind. Children differ from adults in their susceptibility to injuries from blunt trauma, and the injuries themselves differ. By nature of their smaller size, children’s airways are more prone to obstruction, particularly by their relatively large tongues. Their rib cages are more pliable and hence provide less protection to the lungs and mediastinum. Similarly, the abdominal musculature in children is underdeveloped relative to adults, leaving the intra-abdominal organs more vulnerable to injury. Pelvic fractures are uncommon in children; when they do occur, they rarely result in life-threatening bleeding or genitourinary injury.

The cranium of younger children is softer and hence less protective of the underlying brain. Fortunately, open fontanelles in infants provide a limited pressure buffer for children with intracranial hemorrhage or swelling. The relatively large head size, loose ligaments, poor cervical muscular support, and underdeveloped facets result in a different pattern of cervical spine injuries in children than is seen in adults. Although cervical spine injuries in children are uncommon, when they occur, they tend to be higher in the cervical spine and may involve injuries not visible with conventional radiography or computed tomographic (CT) scanning—thus the acronym SCIWORA, for spinal cord injury without radiographic abnormality. The term SCIWORA is somewhat of a misnomer, however, for although these injuries are not visible on radiograph or CT scan, they can be visualized with magnetic resonance imaging.

First 2 Years

Equipment

Because infants and young children are not capable of extended hikes, they are typically transported in carriers. Most front carriers work well from infancy until an age when babies can sit fairly well, typically 6 to 9 months (Figure 99-3). It is important that a front carrier extend up high enough in the back to completely support a young baby’s head. Once a child is sitting well, back carriers are better (Figure 99-4). Back carriers function on the same principle as framed backpacks, redistributing the weight off the shoulders and onto the hips. Many back carriers are able to stand alone and can double as a highchair. Children must be strapped into back carriers, because it is easy for a child to be catapulted out of a carrier if the adult bends over or falls.

FIGURE 99-3 Infants in front carriers.

(Courtesy Judith R. Klein, MD.)

FIGURE 99-4 Toddlers in back carriers.

(Courtesy Judith R. Klein, MD.)

Sleeping bags are available for infants and toddlers. However, in a warm climate, a blanket can suffice, and, in a colder environment, an insulated snowsuit is often adequate. Avoid placing diaper-clad infants into a sleeping bag with an adult; accidents or a leaky diaper can create very unpleasant sleeping conditions. Children, including young infants, also need their own sleeping pads. Such pads protect them from hard, rough ground under the tent and insulate them from the cold ground.

Shoes for young children should protect their feet and allow for full range of movement. The best shoes for toddlers are lightweight and flexible. They need shoes that stay on well, because children can flip their shoes off while in a carrier. Velcro-strapped shoes stay on well and are easy to put on and take off. Because children often lose shoes, an extra pair should be included.

2 to 4 Years

Safety

Unfortunately, 2- to 4-year-olds are notorious for exploring their environment by either wandering off or by trying to become a backcountry gourmet. Young children must be watched closely and cautioned to keep wild mushrooms, plants, berries, and other inedible or toxic items out of their mouths. Children should be kept within sight at all times, as their desire to explore often defies good judgment and exceeds their physical abilities. Although attacks are rare, mountain lions may view small children as easy prey and can strike quickly. Parents should, therefore, discourage their children from wandering ahead unaccompanied. Toddlers should also be encouraged to step only where they can see (i.e., on top of logs rather than over them) to avoid any unsuspecting reptile or large insect.

When selecting campsites, dangerous features, such as steep drop-offs and fast, deep water, should be avoided. Children should be dressed in brightly colored clothing, so they are more easily located if they become lost (Figure 99-5). As children get older, they may carry a whistle to call for help when they are lost. The standard distress signal is three blows to indicate “I’m lost” or “I need help”; the response is two blows to indicate “help is coming.” Parents should teach children to stay put once they discover they are lost and wait to let help come to them. If children panic and start running when they realize they are lost, they increase the chance not only of getting injured but also of traveling farther from the family. The concept of “hug a tree” will be described later in the chapter.

FIGURE 99-5 Appropriate wilderness wear: brightly colored clothing and whistle.

(Courtesy Judith R. Klein, MD.)

School Age (5 Years and Up)

Dehydration

Children are at greater risk of dehydration than are adults. Because the surface area–to-mass ratio of a child is greater than that of an adolescent or adult, insensible fluid losses through the skin account for a larger percentage of total fluid losses as the size of the child decreases. In addition, the sodium concentration of children’s sweat is generally less than that of adults, leading to a greater relative free water loss. Infants are unable to report thirst, an important marker of fluid deficit, thereby increasing their risk of dehydration. Even once they become verbal, children are often preoccupied and fail to report or meet their need for fluids, even when water is freely available.

Hypothermia

Children cool more rapidly than do adults because they have a relatively large surface area and often lack the knowledge and judgment to initiate behaviors that maintain warmth in a cold environment (see Chapter 5). In addition, they have a more difficult time, physiologically, maintaining body temperature in cold climates, predominantly because they do not shiver as effectively.⁴ As a result, parents participating in cold weather recreation with children should be able to recognize, treat, and preferably prevent hypothermia and frostbite.

Hypothermia is defined as core body temperature below 35° C (95° F). At this temperature, the body no longer generates enough heat to maintain body functions. The condition is considered mild when the core temperature is 33° to 35° C (91° to 95° F); moderate at temperatures between 28° and 32° C (82° and 90° F), and severe when it is less than 28° C (82° F). The signs and symptoms of hypothermia are listed in Table 99-4, although these may be quite variable. The most important clue to significant hypothermia is altered mental status. An infant may become lethargic and difficult to arouse. An older child may be shivering, stumbling, or appear confused. These signs merit prompt treatment for hypothermia. Of note, the presence or absence of shivering is not a reliable marker of the severity of hypothermia. Physicians should also caution parents that hypothermia can develop at moderate ambient temperatures if adverse climatic conditions are compounded by illness, fatigue, dehydration, inadequate nutrition, or wet clothing.

TABLE 99-4 Signs and Symptoms of Hypothermia*

* Data from adult subjects.

Prevention

When preparing for cold weather activities, children should dress in layers to allow clothing to be added or subtracted as necessary (Figure 99-6). This avoids excessive perspiration while maintaining warmth. An inner, wicking layer should be followed by a middle, insulating layer and, finally, by an outer, protective layer.

FIGURE 99-6 Layering of clothing for cold environments.

(Courtesy Judith R. Klein, MD.)

Because children generally avail themselves of any opportunity to get wet, clothing that maintains low thermal conductance when moist is particularly important. Conductive heat loss may increase fivefold in wet clothing and up to 25-fold if the child is completely immersed in water. Traditional wool retains warmth when wet because of its unique ability to suspend water vapor within the fibers; however, it is heavier than synthetics and takes much longer to dry. Cotton has a high thermal conductance that increases greatly when wet and is, therefore, a poor choice for wilderness activities in cold weather. Synthetic materials (polypropylene, Capilene, Thermax, Coolmax) wick moisture away from the skin and dry quickly, making them ideal for an inner layer. Finely woven merino wool also provides these same advantages as a wicking layer. The middle, insulating layer may incorporate wool, polyester pile or fleece, down, or similar materials. Finally, windproof and water-resistant outer garments (e.g., Gore-Tex) decrease heat loss from convection and keep children dry. Hats and mittens are also essential; the uncovered head of a child dissipates up to 70% of total body heat production at an ambient temperature of 5° C (41° F).⁴

Frostbite

Localized cold injury can result in frostbite (see Chapter 8). Predisposing factors include wet skin, constricting garments that hinder blood circulation, fatigue, dehydration, contact with cold surfaces, and wind. If skin temperature drops below 10° C (50° F), cutaneous sensation is generally abolished and injury may go unnoticed. Skin cooled to −4° C (25° F) freezes.

Frostbite has traditionally been divided into degrees of injury, much like burns. Determination of depth of injury should occur 24 to 48 hours after rewarming; prior to this, frostbitten skin generally appears hard and feels numb. Skin with superficial frostbite is typically swollen, pink or erythematous, painful, somewhat warm, and often blistered. Sites with deep frostbite are cooler, not edematous, pale, anesthetic, and do not have blisters or bullae. In children, frostbite that extends into bone may affect the growth plate and result in skeletal deformities.⁴ Verbal children will frequently report cold hands and feet, but adults should be vigilant about checking the extremities and noses/ears of nonverbal children, particularly those poorly visible in back carriers. A mirror, frequently used, can assist in this regard. Reports of small children developing frostbite and hypothermia while being carried on the backs of adults engaged in outdoor winter pursuits are not infrequent.

Hyperthermia

Families participating in wilderness activities in hot climates must take special precautions to avoid heat illnesses (see Chapters 10 and 11). Children do not tolerate the demands of exercise in the heat as well as adults. They generate more heat per kilogram and are less able to disperse heat from the core to the periphery. Parents planning wilderness ventures with children in hot climates can follow some simple guidelines for avoiding heat illness. The most obvious entails reducing the duration and intensity of activities under conditions of high climatic heat stress. The likelihood of heat illness depends on relative humidity, wind velocity, and radiant heat, as well as standard dry-bulb thermometer temperature. Figure 99-7 gives a rough guide for activity levels based on temperature and relative humidity.

FIGURE 99-7 Activity levels based on temperature and relative humidity.

Sun Damage

Hazards of overexposure to sunlight include sunburn, photoaging, skin cancer, and phototoxic and photoallergic reactions (see Chapter 14). Climatic changes such as global warming and ozone degradation have increased these hazards.⁵⁴ Preventing ultraviolet damage to skin should begin in childhood, as 50% to 80% of a person’s lifetime sun exposure occurs before 21 years of age.^25,48 Adolescence is the period when children are most at risk. In one study, 83% of children 12 to 18 years old reported at least one sunburn per summer; 36% reported three or more sunburns per summer.²⁵ Recent evidence suggests that the risk of developing malignant melanoma increases significantly with the number of sunburns in childhood.¹⁹ This risk is even higher if a child is light-skinned with a propensity to burn rather than tan. Tolerance to sun exposure is determined by the amount of melanin in skin and ability of skin to produce melanin in response to sunlight. In general, children have lower melanin levels and thinner skin than do adults and are, therefore, at greater risk of sun damage.

The ultraviolet wavelengths UVA and UVB are principally responsible for the harmful effects of solar radiation. UVB is primarily responsible for suntan and sunburn and also promotes development of skin cancer and skin aging. UVB increases 4% for every 1000-foot (300-m) gain in elevation above sea level. Therefore, a backpacker at 10,000 feet (3050 m) will have a 40% increase in UVB exposure. UVA, which is 10 to 100 times more abundant than UVB, is only 0.001 as potent at inducing sunburn. It is also less affected than is UVB by changes in season or solar zenith angle. UVA is primarily responsible for photosensitivity reactions and solar urticaria. It also contributes to skin cancer and skin aging. A number of drugs often used in adolescence, such as tetracycline, vitamin A derivatives (Retin-A, Accutane), and nonsteroidal antiinflammatory drugs (NSAIDs), increase the risk of photosensitivity reactions and the need for UVA protection. Consequently, it is important to use sunscreens that protect against both UVA and UVB.

The harmful effects of ultraviolet radiation from the sun can be reduced if parents are educated regarding the dangers of sun exposure and encouraged to use sun-protective clothing and sunscreens early in their children’s lives. One study demonstrated 60% reduction in childhood sunburns with good parental role-modeling and sunscreen vigilance.⁴⁸ Regular use of sunscreen with sun protection factor (SPF) of at least 15 for the first 18 years of life reduces a person’s lifetime risk of developing nonmelanoma skin cancer by 78%.²⁷

Prevention

The most effective means of preventing sun damage is use of protective clothing and avoidance of excessive sun exposure. Midday hours, particularly around highly reflective surfaces (e.g., water, sand, snow), at high altitude and at the equator are the most dangerous in terms of quantity of ultraviolet exposure. Shady areas should be used for activities during these times. Hats with wide brims and neck drapes help to protect the face and neck from sun exposure (Figure 99-8). Clothing made from tightly woven fabrics is more protective than is clothing made from loosely woven fabric. For example, loosely woven fabrics, such as those used in most T-shirts, have an SPF of only 5. Most clothing loses more of its sun protective effect when wet. Several manufacturers are marketing high-SPF (25 to 50) protective clothing (http://www.coolibar.com; http://www.sunprotectiveclothing.com). This specialized clothing is cool and lightweight, dries quickly, and can maintain its full SPF capabilities when wet (Figure 99-8). Caution is advised on overcast days, because 80% of the sun’s rays still reach the earth even when the sun is not visible.²⁷ In addition, because clouds filter out heat from infrared rays, children feel more comfortable and tend to stay out longer, therefore increasing their overall UV exposure.

FIGURE 99-8 Child with appropriate sun wear: protective clothing, wide-brimmed hat, and sunglasses.

(Courtesy Judith R. Klein, MD.)

Proper eye protection is often overlooked in infants and young children. Excessive ultraviolet light, particularly during snow and water activities, can result in ultraviolet keratitis (see Chapter 28) with even brief exposures. Properly fitting sunglasses that transmit less than 10% of ultraviolet rays should be part of a child’s outdoor activity armamentarium (Figure 99-8). Side shields and polarizing lenses are particularly important in snow conditions.

Sunscreens

Sunscreens formulated with a variety of different agents to prevent UV damage to the skin include physical blocks, chemical blocks, and antioxidants. Physical blocks, such as zinc oxide and titanium dioxide, reflect ultraviolet light and do not penetrate the skin. Chemical blocks prevent ultraviolet light from entering skin, and are themselves absorbed into skin. Chemical blocks have ingredients that block UVB, UVA, or both. Agents that block UVB include PABA, cinnamates, salicylates, and anthranilates; those that block less potent UVA rays include avobenzone and the anthranilates. Benzophenones, oxybenzone, and the physical blocking agents protect against both UVA and UVB.²⁷ Antioxidants present in sunscreens include Vitamins C and E, resveratrol, and pomegranate. These agents help to repair skin damage. Sunscreens that combine protective ingredients with antioxidants are the most effective. The sun protection factor (SPF) is a measure of a sunscreen’s effectiveness. It is measured in terms of the minimal dose (in length of time) of UV radiation required to cause skin erythema. Sunscreens with SPF 30 or higher provide a superior degree of photoprotection and almost completely prevent cellular changes seen with sunburn.²⁷

Overall, there is little difference between child and adult sunscreens except for price. Parents should select sunscreens based on ingredients. Physical blocks are preferred for children because they are difficult to wash/rub off and do not degrade in the sun. Therefore, they do not need to be reapplied with as great frequency as do chemical sunscreens. Zinc oxide can be quite colorful, whereas titanium dioxide is colorless. Apply a thick coat of sunscreen at least half an hour before outdoor activity. Sunscreens must be applied in adequate quantity to provide the SPF indicated on the bottle.⁵¹ Select a sunscreen with an SPF of at least 15, but preferably greater than 30. Waterproof sunscreens are preferred if children are anywhere near water, because these products maintain efficacy for up to 80 minutes of water immersion. Sunscreens should be reapplied at least every 2 hours (or more frequently) during prolonged water immersion or excessive sweating. Cream and lotion sunscreens provide superior coverage to spray-on formulations because they can be applied evenly and in the quantities required to provide effective sun protection. Infants younger than age 6 months should be outfitted with hats and protective clothing and should placed in the shade. Sunscreens in this age group should be limited to small areas of skin only, because infant skin is thin and chemically sensitive.

Drowning

According to the Centers for Disease Control, drowning (see Chapter 75) is the number two cause of injury-related death in children, resulting in more than 900 fatalities in children under 14 in 2005.⁶⁶ Of all deaths among children age 1 to 4 years in 2005, 30% were the result of drowning.⁶⁶ Those most at risk are unsupervised toddlers and male teenagers, in particular, those with inadequate swimming skills and poor judgment. Morbidity and mortality result from asphyxiation, hypothermia, and/or trauma.

If a child is pulled from the water after a submersion event, cervical spine precautions should be maintained unless the event is witnessed and no trauma has occurred. All children who have experienced a period of near-drowning should be transported to a hospital for observation, particularly if they demonstrate any sign of distress. If the child is apneic or pulseless, CPR should be initiated immediately and the child transported to an emergency care facility as quickly as possible. All wet clothing should be removed and rewarming initiated. Prognostic assessments based on the initial appearance of the child should not be made in the field, particularly in the setting of cold water immersion. The exception would be in a remote wilderness area, where transport and evacuation times may be extremely long. Survival with good neurologic outcome has been documented in children with prolonged (>40 minutes) submersion in cold water. The emphasis in the field should be on rapid rescue and immediate CPR.

High-Altitude Illness

High-altitude illness (see Chapter 1) can be viewed as a continuum from acute mountain sickness (AMS) to life-threatening conditions such as high-altitude pulmonary edema (HAPE) and high-altitude cerebral edema (HACE). AMS usually develops within 24 hours of ascent. The incidence and severity of AMS depend on individual susceptibility, as well as rate of ascent and altitude attained. In one study, 37% of children who ascended rapidly to 3500 m (11,500 feet) developed AMS.⁶ Other studies have shown even higher incidences of AMS in children and have suggested that children are more susceptible to hypobaric hypoxia than are adults.⁴³

Bites and Stings

Bites and stings occur commonly in the pediatric age group. In 2008, the American Association of Poison Control Centers reported that more than 25,000, or roughly one-third, of reported bites and stings occurred in individuals under the age of 20 years.⁸ Remarkably, no fatalities were reported in this age group. This emphasizes the need for appropriate triage to determine which children require aggressive therapy so that potentially harmful field interventions can be avoided.

Dangerous interactions between children and surrounding fauna can be limited by judicious use of protective clothing, sturdy footwear, appropriate chemical barriers, and education. These principles apply to snakes, bees, wasps, yellow jackets, mosquitoes, and ticks.

Mosquitoes

Mosquitoes not only present a high nuisance potential but also serve as vectors of disease (see Chapter 48). A number of steps can be taken to avoid mosquito bites and the diseases they carry (Box 99-2). A proper wardrobe provides an excellent physical barrier and is the first defense against mosquitoes. This should include ankle-high footwear, pants cinched at the ankles or tucked into socks, a long-sleeved shirt, and a full-brimmed hat. Mosquito head netting draped over a child’s hat will protect the face and neck (Figure 99-9). Mosquito netting, especially in the sleeping area, has been found to reduce the mosquito attack rate by 97%.⁵⁹

BOX 99-2 Mosquito Avoidance

• Wear hat, long-sleeved shirt and pants. Tuck pants into socks.

• Minimize outdoor activities at dusk.

• Use mosquito netting to cover the heads of infants and children and the sleeping area.

• Soak or spray clothing, netting, and screens with permethrin (Permanone or Duranon).

• Use insect repellents with picaridin or no more than 35% DEET on exposed skin only, avoiding children’s hands.

• Apply repellents over any other creams such as sunscreen to minimize absorption and maximize the repellent effect.

• Keep repellents out of reach of small children.

DEET, N,N-diethyl-m-toluamide.

FIGURE 99-9 Mosquito netting draped over a child’s hat.

(Courtesy Judith R. Klein, MD.)

Repellents containing DEET (N,N-diethyl-m-toluamide) are effective against mosquitoes, ticks, black flies, and many other arthropods. Although generally of low toxicity, high concentrations of DEET can cause dermatitis with erythema, bullae, skin necrosis, and residual scarring. DEET is also absorbed cutaneously, and rare toxic encephalopathy associated with its use has been reported. A large study based on data from the American Association of Poison Control Centers refuted the commonly held belief that children are more susceptible to DEET toxicity. The study demonstrated that children actually have less severe outcomes after DEET exposures than do adults.⁵ Although products containing 100% DEET are commercially available, long-acting formulations of ≤35% DEET appear equally effective in protecting against mosquitoes, with much less potential for toxicity.^47,63 Although available data do not permit precise safety guidelines, infants younger than 6 months should avoid DEET, but those older than 6 months can use products with up to 30% to 35% DEET. The repellent effect can last up to 8 hours, but heavy perspiration or swimming should prompt reapplication every 6 to 8 hours. Dawn and dusk are particularly risky times; outdoor activities should be limited at these times if possible. Parents should not allow children under 8 years old to apply DEET to themselves, because of the risk of DEET exposure to eyes or mouth in this age group. DEET products can be applied over other creams such as sunscreen to minimize absorption and maximize repellent effect. Parents should also be cautioned to keep DEET out of the reach of small children, because ingestion may be fatal.

Picaridin (Bayrepel) is a more recently developed alternative to DEET. Commonly used in Europe and Australia, it is odorless, minimally toxic, and considered by the World Health Organization (WHO) and the U.S. Environmental Protection Agency (EPA) to be an effective insect repellent. Anecdotal reports, however, suggest that it might not be as effective as DEET and may not repel as broad an array of arthropods (e.g., flies). Oil of lemon eucalyptus is an EPA-approved insect repellent, but its efficacy is similar to that of low-concentration DEET products. Therefore, its use is not recommended in areas heavily infested with mosquitoes. Other alternative insect repellents are widely available and often more appealing to parents, because their active ingredients are “natural.” Unfortunately, agents such as citronella, lavender oil, and soybean oils have demonstrated very limited efficacy in repelling arthropods.⁵⁹ Although natural products may be acceptable in areas where mosquitoes do not carry disease, in U.S. areas with persistently active West Nile Virus, and certainly in much of the tropical developing world where malaria and dengue fever are endemic, these products are simply inadequate. In addition, the above oils have been associated with aspiration pneumonitis when accidentally ingested by young children.

The pesticide permethrin, available as a 0.5% spray or soaking liquid (Permanone, Duranon Tick Repellent), is safe and effective against arthropods, especially ticks. Unlike DEET repellents, these permethrin products are applied to fabric or netting, not to skin. Permethrins as a class have low toxicity in mammals. The combination of DEET applied to exposed skin and permethrin treatment of clothing is particularly effective in protecting against mosquito bites and ticks. This combination can reduce mosquito bites by up to 99% for up to 8 hours.⁵⁹ The protective effect of mosquito netting is also greatly enhanced when the netting is impregnated with permethrin. These effects are longer lasting with permethrin soaks (up to 20 washings) than with permethrin spraying of clothing or netting.

West Nile Virus (WNV) continues to be a concern across the United States, although the number of cases (>700 in 2009) and fatalities (33 in 2009) have dropped since the peak in 2006 (see Chapter 48).⁶⁷ WNV is a zoonotic disease transmitted from animal hosts to humans via infected Culex mosquitoes. Twenty percent of infected individuals develop a mild nonspecific febrile illness lasting less than a week. More than one-half of reported cases in 2009 developed neurologic manifestations.⁶⁷ Protection against mosquito bites is the only means of prevention of WNV-related disease in humans.

General Recommendations

Physicians should emphasize to families that risk avoidance is the most important aspect of safe travel. The basic tenets of safe foreign travel with children are listed in Box 99-3. Parents should select transportation, activities, and overnight settings carefully to avoid unnecessary hazards. Freshwater swimming should be avoided in developing countries to prevent parasitic infections such as schistosomiasis. Where swimming is appropriate, parents should provide close supervision. In one study in Washington State, drowning was the leading cause of pediatric mortality in the wilderness, followed by closed head injury and exposure.⁴⁶ Because traumatic injury is the leading cause of morbidity and mortality among children, prevention is key. Protective devices such as car seats, helmets, personal flotation devices, and protective clothing and pads should be used as often as possible (Figure 99-10). Do not assume any of these items is available in the destination country. Skin protection is also vital in the outdoors, particularly in tropical environments. The use of closed shoes can prevent infections with various hookworms, Strongyloides, and other parasites that enter through the skin. Closed shoes also protect feet from injuries that can result in wounds infected with Staphylococcus aureus and other organisms that grow vigorously in the tropics. Clothing should be selected carefully based on ambient temperature and expected conditions. Even in hot, sunny climates, light, high-SPF clothing should cover as much body surface as possible to provide protection from parasites, insects, and ultraviolet light. Sunscreen should be used liberally and reapplied every few hours, particularly after swimming.

FIGURE 99-10 Appropriate helmet use by a child.

(Courtesy Judith R. Klein, MD.)

Parents should be advised to take great care in selecting foods and safe drinking water for themselves and their children, who are particularly vulnerable to disease (Box 99-4). All foods should be either well cooked, canned, or peeled. All milk products should be either pasteurized or boiled to avoid diarrheal illness and tick-borne encephalitis. Water should never be consumed from the tap; only bottled, 1-minute-boiled, or ultraviolet (SteriPEN) or chemically treated (iodine) and microfiltered (0.2-µm pore size) water should be ingested. In certain areas, even bottled water is suspect. Breastfeeding is safest for young infants. If formula is used, only properly disinfected water should be used for its preparation. Finally, good and frequent hand-washing, particularly with infants and toddlers and especially around mealtimes, successfully interrupts the fecal–oral passage of disease.

Parents should also focus their efforts on avoiding contact between their children and insects or wild animals. Mosquitoes and ticks can be avoided by limiting outdoor activities between dusk and dawn and by wearing protective clothing and repellent (see Box 99-2). As mentioned previously, DEET is an effective repellent but should not be used at concentrations greater than 35% in children because of the risk of toxicity.⁵⁹ Children’s hands should be free of DEET to prevent accidental eye and mouth contact. Picaridin is an alternative but anecdotal reports have suggested that it is not as effective as DEET and scientific studies have not confirmed its efficacy against flies (e.g., tsetse). Therefore, it should not be considered the repellent of choice in areas with disease-carrying insects. Outer clothing and bed netting should be treated with permethrin. Check for ticks daily when in tick-infested areas. Children should be warned to watch where they place their hands and feet (in crevices, unattended shoes, sleeping bags) to avoid the unexpected arthropod or snake.

Immunizations

Foreign travel with children requires advance planning because vaccines recommended for travel to certain countries may take up to 6 weeks to complete. The Centers for Disease Control and Prevention (CDC) website (http://www.cdc.gov/travel) provides up-to-date information on immunizations and prophylaxis based on the following:

Vaccines may be categorized as routine (hepatitis B, polio, diphtheria–tetanus–pertussis, Haemophilus influenzae B, pneumococcus, rotavirus, measles–mumps–rubella, varicella, hepatitis A, meningococcus), seasonally or geographically indicated or required (influenza, yellow fever, typhoid, immunoglobulin [Ig]), and indicated for extended stay (Japanese encephalitis, rabies)⁶⁴ (Table 99-6). The indications, dosages, and schedules for administration of these immunizations are listed in Table 99-7. The risk of acquiring diseases covered by many routine childhood immunizations is greater when traveling to developing countries because of inconsistencies in local immunization practices and subsequent loss of herd immunity. Children who have not completed their primary series of immunizations may require acceleration of the vaccination schedule or extra doses to maximize protection before travel. The minimum age at which some vaccinations can be given is listed in Table 99-7. In addition, seasonal influenza A vaccine should be given to all children older than 6 months traveling during influenza season: December to April in the northern hemisphere and April to October in the southern hemisphere. Rotavirus vaccine (Rotateq) is also strongly recommended for young infants traveling abroad. Rotavirus is the most common cause of acute gastroenteritis (AGE) in young children, with 80% of children infected by the age of 5 years prior to vaccine introduction.¹⁵ In the developing world, it is responsible for the deaths of more than 500,000 children under 5 years. As with many other diseases, children are more likely to develop AGE while traveling, so vaccination is an important preventive tool. Finally, the vaccine against meningococcus (MPSV4 or MCV4), now routine in adolescents, should be administered to all children older than age 2 years traveling to endemic areas or locales with regional epidemics. If travel to such an area is essential for a younger child, the vaccine (MPSV4) does have some, albeit modest, efficacy in infants as young as 3 months.⁶⁴ Generally, children younger than age 2 years should avoid travel to such areas.

TABLE 99-6 Categories of Vaccines for Children

From U.S. Centers for Disease Control and Prevention (http://wwwnc.cdc.gov/travel/yellowbook/2010/chapter-7/vaccine-recommendations-for-infants-and-children.aspx).

Ideally, a medical visit to discuss travel plans and start immunizations should be made 6 weeks before travel. Not all immunologic agents recommended for travel are compatible and some require multiple doses. Therefore, selection of immunizations to be given at any one time and the interval between immunizations are important. Table 99-8 presents recommendations for the timing and sequence of specific travel immunizations. In general, all toxoid, recombinant, inactivated, and live-attenuated vaccines may be given simultaneously. Live-attenuated vaccines should be given either simultaneously or at least 30 days apart to avoid reduced immunoreactivity to each vaccine.

TABLE 99-8 Recommended Timing and Sequence of Non-routine Immunizations for Foreign Travel

Give only immunizations indicated for area of travel, length of stay, and age of child.

Simultaneous administration of routine and travel-related vaccines is acceptable with the exception of measles–mumps–rubella vaccine or varicella vaccine with Ig. Administer Ig at least 3 weeks after these live virus vaccines.

In the United States, hepatitis A vaccine is recommended for children older than age 2 years. Of note, the World Health Organization (WHO) recommendations include children age 1 year and older. For children younger than age 1 year or for those unable to receive this vaccine more than 2 weeks before travel, Ig can provide passive hepatitis A prophylaxis. Administration of Ig interferes with the humoral response to some of the live-attenuated virus vaccines, such as measles, mumps, and rubella (MMR) and varicella. If Ig is given first, then these vaccinations should be delayed by at least 6 weeks, and preferably by 3 months, to obtain an adequate immunogenic response.²² When both are needed for travel, it is best to give MMR or varicella vaccine first; the Ig can be given closer to the time of travel, at least 2 weeks and preferably 4 weeks later. Ig does not interfere with antibody production after oral polio or yellow fever vaccines and may be given at the same visit. Yellow fever vaccination is often a requirement for travel to certain countries in Africa and South America. Infants older than age 9 months can receive this live virus vaccination, but younger infants are at risk for vaccine-related encephalitis and should not travel to areas where yellow fever is endemic.⁶⁴

Prophylaxis: Malaria

Globally, malaria infects roughly 300 million people each year and results in 1 million deaths.⁶⁸ Children younger than 5 years are particularly vulnerable and represent more than 75% of the fatalities from this disease. In fact, in Africa, malaria is responsible for 20% of all childhood deaths. The risk of acquiring malaria (see Chapter 49) during visits to developing countries in the tropics is significant. Even areas where the overall risk is relatively low may have foci of intense transmission. Of the more than 10,000 cases of malaria diagnosed in the United States and reported to the CDC between 1997 and 2006, nearly 60% came from Sub-Saharan Africa, 14% from Asia, and 13% from Caribbean nations.⁴¹ In 2007, 20% of the roughly 1500 cases of malaria in the United States reported to the CDC were in children.

Protective measures to prevent mosquito bites help interrupt the transmission of malaria but are not foolproof (see Box 99-2). Therefore, chemoprophylaxis is highly recommended for travelers to countries where malaria is endemic. Plasmodium falciparum and Plasmodium vivax are the two species most often responsible for malaria. The most lethal plasmodium, P. falciparum, has developed widespread resistance to chloroquine and in some areas (extreme northern and southern Thailand, Cambodia, Burma) resistance to mefloquine. Therefore, the choice of prophylactic agent is based primarily on the presence of resistant malaria in the area of travel. The age/weight and medical history of the child are additional determinants of the appropriate prophylactic agent. Table 99-9 lists the available options for malaria chemoprophylaxis.

TABLE 99-9 Malaria Chemoprophylaxis

Medication	Indications/Contraindications	Dosing
Chloroquine (Aralen) (liquid form is Nivaquine—not available in United States)	Travel to chloroquine-sensitive areas (Caribbean, Central America north of Panama, Middle East)	5 mg base/kg q wk up to 300 mg for 1 wk before until 4 wk postexposure; 10 mg/ mL-form available outside United States
Mefloquine (Lariam)	Travel to chloroquine-resistant/mefloquine-sensitive area. Do not use in setting of epilepsy, psychiatric illness, cardiac arrhythmias	Give 1 wk pre- until 4 wk post; q wk
		Dosage:
		5-10 kg (11-22 lb): 5 mg/kg/wk
		10-20 kg (22-44 lb): tab q wk
		20-30 kg (44-66 lb): tab q wk
		30-45 kg (66-99 lb): tab q wk
		>45 kg (>99 lb): 1 tab (250 mg)
Atovaquone (A) + Proguanil (P) (Malarone)	Travel to chloroquine- or mefloquine-resistant areas Contraindicated if creatinine clearance <30 mL/min	Pediatric tab dosing: 62.5 mg A/25 mg P
		5-8 kg (11-18 lb): tab qd
		8-10 kg (18-22 lb): tab qd
		10-20 kg (22-44 lb): 1 tab qd
		21-30 kg (46-66 lb): 2 tabs qd
		31-40 kg (68-88 lb): 3 tabs qd
		>40 kg (>88 lb): 1 adult tab qd
		2 days pre- until 7 days postexposure
Doxycycline	Travel to chloroquine- or mefloquine-resistant areas; >8 yr of age only. Beware photosensitivity	2 mg/kg/day up to 100 mg/day 1-2 days preexposure and for 4 wk after exposure
Pyrimethamine–sulfadoxine (Fansidar)	Standby for treatment if malarial symptoms develop and medical attention >24 hr away Contraindicated if age <2 mo or sulfa allergy	Single dose:
		2 mo-1 yr: tab
		1-3 yr: tab
		4-8 yr: 1 tab
		9-14 yr: 2 tabs
		>14 yr: 3 tabs
Primaquine	Prevention of relapse with P. vivax or P. ovale Use after prolonged stay in malaria-endemic area Avoid if G-6-PD deficient	0.6 mg/kg/day for 14 days

G-6-PD, Glucose-6-phosphate dehydrogenase; q, every; qd, every day.

Data from Centers for Disease Control and Prevention: Information for health care providers: Prescription drugs for malaria. http://wwwnc.cdc.gov/travel/yellowbook/2010/chapter-2/malaria.aspx#990.

If a child is traveling to a chloroquine-sensitive area, such as the Caribbean, parts of Central America, or the Middle East, then chloroquine (Aralen) is the drug of choice. Chloroquine prophylaxis should be given weekly, starting 1 week before travel and continued for 4 weeks thereafter. Chloroquine passes through breast milk, but not in sufficient quantities to protect an infant. Therefore, a breastfed infant should receive chloroquine prophylaxis in standard recommended doses (see Table 99-9). Chloroquine is not readily available in a liquid form in the United States. The powder, which is extremely bitter, may be suspended in a syrup or mixed with food. Instant pudding effectively masks the bitter taste and makes the medicine more palatable. An acceptable-tasting chloroquine liquid (Nivaquine) is available outside the United States. Chloroquine should be kept out of the reach of children. As little as 300 mg may be fatal in small children.⁵⁵ If a toxic chloroquine ingestion occurs, the child should be transported promptly to a medical facility.

For children traveling to chloroquine-resistant areas, the next question is whether they are traveling to a mefloquine-resistant area as well. This includes parts of Myanmar (Burma), Cambodia, and Thailand. If the area is mefloquine sensitive, then mefloquine (Lariam) is a good option. The advantage of mefloquine is that it is dosed weekly, from 1 to 2 weeks before travel until 4 weeks after return. It should be avoided in children under 5 kg (11 lb) and those with psychiatric illnesses, epilepsy, or underlying cardiac arrhythmias. If the area is mefloquine resistant (or mefloquine sensitive, but either contraindications to mefloquine exist or parents prefer not to use mefloquine), then the two options are atovaquone plus proguanil (Malarone) or doxycyline. Malarone is approved in the United States for children more than 5 kg (11 lb) in weight, but requires daily administration. It must be taken 2 days before entry into a malarial area and continued for 7 days after leaving. It is contraindicated in the setting of severe renal impairment (creatinine clearance, <30 mL/min). Both Malarone and mefloquine are available in tablet form only, but tablets may be administered crushed. Alternatively, a compounding pharmacist may prepare the child’s dose in a gelatin capsule and the contents of the capsule can be placed in food just prior to administration. Doxycycline is indicated for children older than age 8 years traveling to mefloquine-resistant areas or with contraindications to mefloquine or Malarone use. It also must be dosed daily. It should be started 1 to 2 days before and continued for 4 weeks after travel to a malarial area. Side effects include diarrhea and photosensitivity. With all antimalarials, particularly those dosed daily, timing of medication ingestion is critical. Medications should be taken at the same time each day/week, to avoid a drop in blood levels below the level of efficacy. Given the difficulties in administering medications to children, weekly dosing (mefloquine) may be preferable when it is an option. The importance of proper prophylaxis against malaria cannot be overemphasized. In a review of pediatric malaria cases, 75% to 100% of patients had received no or inadequate chemoprophylaxis.^18,58

In the event that a child develops an acute febrile illness in a malaria-endemic area where medical care is not immediately available, pyrimethamine-sulfadoxine (Fansidar) may be used as standby treatment. Fansidar is given as a one-time dose. Prophylaxis with this drug is not recommended because of the risk of Stevens–Johnson syndrome. Fansidar should not be given to an infant younger than age 2 months or to anyone allergic to sulfa medications. Malarone is an alternative standby treatment that has been used successfully in Fansidar-resistant areas (parts of Southeast Asia and the Amazon basin).⁷ All patients who take Fansidar or Malarone for presumptive treatment of malaria should be transported to a medical facility as soon as possible for definitive care. Of note, artemisinin-derived agents are not available in the United States except under special circumstances for severe malaria in hospitalized patients. They are not used for prophylaxis because the short half-lives of these agents would require multiple daily doses.

Primaquine is an antimalarial drug used to prevent emergence of P. vivax and P. ovale after heavy or prolonged (many months) exposure to mosquitoes. Routine chemoprophylaxis does not kill the exoerythrocytic stages of these Plasmodium species. Primaquine is taken daily for 2 weeks after leaving a malarial area. Primaquine should not be given to anyone with glucose-6-phosphate dehydrogenase (G-6-PD) deficiency.

Motion Sickness

Motion sickness can occur with air, land, or sea travel (see Chapter 83), particularly in children ages 2 through 12 years. Emotional upset, noxious odors, and ear infections can make symptoms worse. Children experiencing motion sickness are often pale and diaphoretic, and they feel nauseated and weak. They may vomit, but unfortunately this does not provide prolonged relief. Children known to be susceptible to motion sickness should be seated in the middle or near the front of the boat, plane, or car, where motion is minimized. They should be encouraged to look at objects far away and avoid focusing on close objects such as books. Some children get significant relief from using headphones to listen to music or stories.

Dimenhydrinate (Dramamine, 1.0 to 1.5 mg/kg) administered 1 hour before departure and repeated every 6 hours can help those known to be prone to motion sickness. If dimenhydrinate is not available, diphenhydramine (Benadryl, 1.25 mg/kg every 6 hours up to 50 mg) may also be effective. Both medications may cause drowsiness, and diphenhydramine occasionally causes paradoxical excitability in children. Scopolamine patches, commonly used in adults, should not be used in children because children are particularly susceptible to the side effects of belladonna alkaloids. It has been postulated that this particular administration system might release too much scopolamine and, consequently, produce serious side effects in children.

Eustachian Tube Dysfunction

Eustachian tube dysfunction is the result of disequilibrium between pressure in the eustachian tube and the surrounding atmospheric pressure. If atmospheric pressure rises (e.g., with descent in an airplane) and the pressure within the tube does not rise as quickly as the ambient pressure, the eustachian tube becomes compressed. If compressed enough, the eustachian tube cannot equalize pressure in the middle ear with that of the environment, resulting in a sense of compression on the outer aspect of the tympanic membrane. Far more children than adults (nearly 15% of the pediatric population) suffer from this problem, because of the relatively smaller, and hence more compressible, pediatric eustachian tube. Swallowing often helps relieve the pressure disequilibrium and may be facilitated by drinking, sucking on a pacifier, or, for the breastfed infant, by nursing. Older children may wish to chew gum or yawn to equalize middle ear and atmospheric pressure. Contrary to popular belief, decongestants are not useful with eustachian tube dysfunction in children and should generally be avoided in young children.⁹

Traveler’s Diarrhea

Traveling to wilderness areas or developing countries requires leaving behind modern sanitation and reliably disinfected tap water. Unfortunately, this places travelers at increased risk for diarrheal illness (see Chapter 68). Up to 60% of children younger than age 3 years develop prolonged diarrhea (>10 days) during travel in tropical or subtropical areas.^2,11 This risk is highest in young visitors to Africa and India, followed by travelers to Asia and Latin America. Young children are at greater risk for traveler’s diarrhea (TD) and its complications because of their relatively poor hygiene, oral exploration, immature immune systems, lower gastric pH, more rapid gastric emptying, and difficulties with adequate hydration.

TD is defined by the National Institutes of Health (NIH) as a twofold or greater increase in the frequency of unformed stools, or any number of such stools when accompanied by symptoms of fever, abdominal cramping, vomiting, or blood or mucus in the stools. In small children, the course tends to be more severe and prolonged, lasting from 3 days to 3 weeks.² The majority (>80%) of TD is caused by bacteria, followed by parasites (10%) and viruses (5% to 8%) (Table 99-10). Enterotoxigenic Escherichia coli alone is responsible for 50% of TD.⁴⁰ Shigella and Campylobacter are also prominent causes of TD, along with rotavirus and norovirus. Giardia is by far the most common parasitic cause of TD and is more indolent in onset.

TABLE 99-10 Causes of Traveler’s Diarrhea in Children

* Most common.

Constipation

Although not as serious a problem as diarrhea, constipation can be a significant and uncomfortable issue for children during travel. Several factors can contribute to development of constipation:

Constipation is defined as decrease in stool frequency and increased firmness of the stool. Firm stool is more difficult to pass and can result in painful anal fissures and hemorrhoids. Children who experience anal pain during defecation may choose to retain stool, exacerbating the constipation problem.

The best approaches to constipation are prevention and, if that fails, early management. To prevent constipation, parents should provide safe fruits and vegetables or dried prunes for their children and should actively encourage clean water consumption. Anal fissures and hemorrhoids should be managed with sitz baths, vitamin A&D ointment, and antiinflammatory hemorrhoidal creams such as Anusol. If these approaches fail, bulk stool softeners (e.g., Metamucil) and, in extreme cases, hypertonic phosphate enemas (e.g., Fleets) can be used in children older than 1 year. Laxatives are not recommended because chronic use can actually result in paradoxical constipation. If constipation is accompanied by severe abdominal pain, distention, vomiting, or fever, children should be brought to medical attention for further evaluation.

Abdominal Pain

Abdominal pain is another common complaint in children. The etiology of abdominal pain ranges widely, from extremely benign viral infections or constipation to serious or life-threatening conditions such as appendicitis or ectopic pregnancy. Caregivers accompanying children into the backcountry or to developing countries should be taught the basic indications for seeking medical treatment for this complaint. Abdominal discomfort accompanied by vomiting or diarrhea may be observed for 12 hours with appropriate hydration. If the pain worsens or fails to resolve, or the child develops a high fever, vomiting for greater than 24 hours, focal abdominal tenderness, or abdominal distention, the child should be brought to medical attention. If a child complains of suprapubic pain and dysuria, a 7-day course of antibiotics (e.g., amoxicillin or ciprofloxacin in older children) may be administered for presumed bladder infection. If the symptoms do not improve in 2 or 3 days, or if high fever or back pain develops, the child should be brought to medical attention because these symptoms suggest pyelonephritis. In adolescent girls, presence of lower abdominal pain, amenorrhea, or vaginal bleeding suggests the possibility of ectopic pregnancy. If this is suspected, immediate medical evaluation is indicated.

Respiratory Infections and Otitis Media

Respiratory tract and otolaryngologic infections are very common in the pediatric population. The majority of infections, including acute otitis media (AOM), sinusitis, pharyngitis, croup, bronchiolitis, and bronchitis, involve the upper respiratory tract. Most of these are viral in etiology; the remainder are the result of infections with Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis.⁵³ Because definitive diagnoses based on otoscopy and auscultation of the lungs often cannot be made in the course of wilderness travel, parents must rely on symptoms and the presence of fever to determine whether treatment is necessary. The presence of high fever, otalgia >2 days, facial pain, sore throat without cough or rhinorrhea, or mucopurulent nasal discharge lasting longer than 10 days probably merits both antimicrobial and symptomatic treatment. It should be noted, however, that 20% to 80% of AOM and 50% of streptococcal pharyngitis cases resolve without intervention.¹⁷ Furthermore, antibiotic treatment of upper respiratory tract infections, such as bronchitis, bronchiolitis, croup, and most pharyngitis, does not shorten the course, minimize symptoms, or decrease complications.⁵³ If streptococcal pharyngitis is suspected on the basis of absence of cough or coryza and the presence of fever, cervical lymphadenopathy, and tonsillar exudate, then antibiotic therapy is warranted. Although antibiotics for streptococcal pharyngitis have minimal effect on the duration of the disease, they reduce the incidence of suppurative complications, such as peritonsillar abscess, and nonsuppurative complications, such as rheumatic fever and post-streptococcal glomerulonephritis.

With increasing use of antibiotics, bacterial resistance to these agents has risen dramatically. Resistance is highly correlated with the rate of antibiotic use in a given population. Ten percent to 50% of S. pneumoniae isolates are resistant to penicillin, and 5% to 35% are resistant to macrolides such as erythromycin.³⁵ Up to 20% of H. influenzae and 70% of M. catarrhalis isolates are resistant to amoxicillin. However, minimal inhibitory concentration (MIC) testing has demonstrated sensitivity to high-dose amoxicillin, even among resistant strains. First-line therapy for suspected bacterial respiratory infection is, therefore, high-dose amoxicillin at 80 mg/kg/day divided into three doses per day. Second-line therapy is high-dose amoxicillin–clavulanate (80 mg/kg/day divided into two doses per day), cefuroxime (15 mg/kg twice a day), or ceftriaxone (50 mg/kg once daily). Uncomplicated AOM in children older than 2 years may be treated for 5 to 7 days; otherwise, the standard treatment for AOM is 10 days, and for sinusitis 14 days.⁵³ Suspected streptococcal pharyngitis can be treated for 10 days with penicillin or amoxicillin, or for 5 days with azithromycin (10 mg/kg on day 1, then 5 mg/kg/day on days 2 to 5).

Often more important to patients than antibiotics are medications for symptomatic relief. Judicious use of acetaminophen (15 mg/kg every 4 hours) and/or ibuprofen (10 mg/kg every 8 hours) along with topical analgesics (e.g., antipyrine-benzocaine otic drops) is strongly recommended.

If influenza is suspected based on season, regional epidemics, and symptomatology (e.g., high fever, respiratory symptoms), parents should consider carrying and administering oseltamivir (3 mg/kg/dose twice daily) to high-risk children. High-risk children are those younger than age 5 years (particularly under 2 years), those with chronic lung or other organ dysfunction, those who are immunocompromised (e.g., HIV, diabetes), and those on chronic aspirin therapy.⁴⁹ Treatment is most effective in reducing length and severity of disease if given within the first 48 hours of illness. Any child with suspected influenza who appears ill or has signs of lower respiratory tract infection should immediately be given oseltamivir and taken to the nearest medical facility.

Fever of Unclear Etiology

High fever that develops in a child during the course of foreign travel may be the result of a common infection (e.g., viral syndrome, pharyngitis) or the manifestation of a tropical disease. Box 99-8 lists the indications for prompt medical attention in a child with fever. If malaria is suspected, the child should immediately be taken to the closest medical facility. If this cannot occur within 24 hours, any child older than 2 months should be given Fansidar as standby treatment as recommended in Table 99-9.

Typhoid fever caused by S. typhi can also manifest with high fever, paradoxical bradycardia, and, at least initially, without diarrhea. Children who appear ill with high fevers may have invasive typhoidal disease and should be treated in a medical facility. Salmonella resistance is rising in developing countries, but strains are typically susceptible to third-generation cephalosporins (e.g., ceftriaxone) and/or quinolones.³⁹

Dengue fever, caused by a mosquito-borne arbovirus, can also cause high fever, headaches, and severe myalgias. With the exception of recurrent dengue, which can result in hemorrhagic complications, the treatment of dengue fever is purely symptomatic. Of note, dengue is a disease found not only in the developing world. The southeastern United States and Hawaii are infested with the dengue-carrying Aedes aegypti mosquito.⁵⁹

Headache

Headache is a common travel-related problem in the adolescent population. The most common causes of headaches in children are febrile illnesses, migraines, dental infections, sinusitis, tension, or fatigue. Life-threatening causes of headache, such as meningitis, spontaneous or post-traumatic intracranial bleeding, or mass lesions, should be considered in any child with this complaint. Parasitic diseases, such as dengue fever and malaria, can also cause severe headache.

A child with a tender tooth or tenderness to palpation of his sinuses should be managed with analgesics (e.g., acetaminophen with or without codeine or ibuprofen) and antibiotics. Dental infections respond well to penicillin and a visit to the dentist for definitive management. (See Respiratory Infections and Otitis Media, earlier, for information on the antibiotic treatment of sinus infections.) If a child has had previous migraine headaches or has a history that is classic for migraine (e.g., unilateral headache, aura, visual scotoma, photophobia, nausea, family history of migraine), analgesics and rest in a quiet, dark room are the appropriate first-line therapies. Caffeine, in the form of a strong cup of coffee, is also a helpful improvisational treatment for migraine headaches. If a child’s headache is accompanied by high fever, neck stiffness, vomiting, confusion, neurologic abnormalities, or a recent history of trauma, the child should be brought to medical attention immediately.

Conjunctivitis

Conjunctivitis, or “pinkeye,” is a common pediatric problem. Most conjunctivitis in children is either allergic or infectious (e.g., adenovirus, Staphylococcus, Streptococcus, or Haemophilus). Itching and clear discharge suggest an allergic etiology best treated with a topical or systemic antihistamine (e.g., diphenhydramine). Absence of itching, along with a slightly thicker or colored discharge from one or both eyes, is more consistent with an infectious cause of conjunctivitis. Distinguishing between viral and bacterial etiologies can be very difficult, so all suspected infectious conjunctivitis should be treated with a topical antibiotic, such as erythromycin ointment (four times a day for 7 days), or polymyxin B sulfate plus trimethoprim (Polytrim) ophthalmic solution (1 drop every 3 hours for 7 days). Drops are preferred when the child is willing to accept them because they do not obscure vision. Eye discharge should be wiped from the eye with a warm moist cloth, and contact precautions should be exercised to prevent spread of what is a very infectious condition until the discharge resolves.

If the presence of a foreign body in the eye is suspected or there is a chemical exposure to the eye, a drop of a topical ocular anesthetic, such as proparacaine, should be applied and the eye flushed vigorously with water. Caregivers should then administer oral analgesics to the child and apply a topical antibiotic ointment or solution for 24 to 48 hours. If the foreign body sensation persists after 1 to 2 days, there is likely to be a retained foreign body and the child should be brought to medical attention. In addition, the presence of eye pain, periorbital swelling, fever, photophobia, or visual blurring with or without a history of antecedent eye trauma or contact lens use suggests a more serious diagnosis and should prompt immediate medical attention.

Rashes

Identification of rashes in children is an art. Although parents cannot be expected to become familiar with all types of rashes, they may be able to distinguish common rashes from potentially dangerous exanthems. Petechial, purpuric, or mucosal lesions are markers for potentially serious diseases and should prompt parents to seek medical attention immediately. Standard dermatology textbooks with photographs can be used to instruct parents to recognize common viral exanthems and rashes caused by varicella, scabies, and contact dermatitis (e.g., poison oak or poison ivy). Scabies can most safely be abolished with permethrin. Contact dermatitis often can be simply treated with 1% hydrocortisone cream and diphenhydramine (see Chapter 63). When dermatitis covers the face, genitals, or large portions of the child’s skin, systemic corticosteroids may be indicated.

Lacerations

Soft tissue injuries are extremely common among children, particularly as they become more ambulatory. All wounds sustained should be thoroughly irrigated with clean water and explored to ensure that no foreign bodies remain. Children with lacerations that require suturing should be brought to medical attention, if it is available. In general, lacerations should not be sutured in the backcountry or in a remote area, outside a medical facility, because of the risk of infection. Such lacerations should be covered with a water-resistant dressing, splinted if located over a joint, and observed. If no evidence of infection develops over 4 to 5 days, the laceration may be repaired by delayed primary closure. One exception is a laceration to the face. The face has an excellent blood supply and infections are rare. After thorough irrigation via a 14G IV catheter attached to a syringe, relatively superficial facial wounds can be approximated with adhesive wound closure strips and then repaired with tissue glue.

If a wound becomes infected, it should be kept elevated and warm compresses applied. Given the rising incidence of multi-drug (in particular, methicillin)–resistant Staphylococcus aureus (MRSA), antibiotics effective against this bacteria should be initiated promptly. Trimethoprim–sulfamethoxazole is an excellent agent. The dosing is 8 to 10 mg of the TMP component/kg/day divided twice daily. Doxycycline (2 mg/kg/day divided twice daily) is an option for children over 8 years of age.

Animal Bites

Bites from stray dogs and other animals are more frequent during travel to the developing world. Prevention techniques primarily involve keeping children away from stray dogs and other wild animals and a strict “no feeding of animals” rule. If a bite occurs, it should be irrigated copiously. In general, lacerations from animal bites should not be repaired primarily, with the exception of certain facial wounds. All victims of animal bites should receive antibiotic prophylaxis, ideally with amoxicillin–clavulanate (80 mg/kg/day divided twice daily) or azithromycin (10 mg/kg on day 1, then 5 mg/kg/day daily for 5 days) in persons who are penicillin allergic.⁶¹

Rabies is endemic in many parts of the world, including much of South and Central America, India, Southeast Asia, and the Phillipines.¹³ Unlike in the United States, where bats and raccoons are the most common carriers, in the developing world, domesticated animals, such as dogs and cats, are most frequently implicated in transmission. All animal bites that occur in rabies-endemic areas, no matter how superficial, mandate postexposure rabies prophylaxis (see Table 99-7 for schedule of vaccination). In fact, any contact between a child and a raccoon, bat, fox, or skunk in an endemic area should be treated as a high-risk event and treated with rabies vaccination.⁶¹ Current CDC guidelines recommend that children traveling to endemic areas for more than a month or those who will be spending a great deal of time outdoors should receive rabies prophylaxis prior to their travels.⁶⁴ If a bite occurs in a child who has been previously vaccinated, then the remaining two doses of the vaccination series should be given. If a bite occurs in a child with no preexposure vaccination, that child should begin the rabies vaccination series and receive rabies immunoglobulin (HRIG: 20 IU/kg with as much as possible in and around the wound and the remainder IM in a large muscle).

Poisoning

In their first few years of life, children explore the environment with their hands and mouths. Plants, flowers, mushrooms, and medications, including those in the pediatric first-aid kit, are all potentially tasty treats to a toddler. Travel into the wilderness expands the repertoire of available objects for a child to orally explore. In an urban environment or during travel in the United States, a call to a poison center (800-222-1222) can provide immediate information regarding the dangers of a particular ingestion and the possible need for emergency evaluation and treatment. In the wilderness and when traveling abroad, particularly in developing countries, this is rarely an option. Because it is unrealistic to expect a parent to know whether a certain medication, cosmetic, plant, or mushroom is toxic, the best advice is prevention.

All medications and cosmetics should be kept out of reach and stored in child-resistant containers. Children should never be enticed to take their own medications by referring to medicines as “candy.” During forays into the wilderness, parents should not let toddlers out of eyesight and should explain to their children why plants or mushrooms should not be put in their mouths. If a child’s skin or eyes are exposed to a toxic substance, the area should be flushed vigorously with clean water for 15 to 20 minutes. Ipecac syrup, a powerful emetic and once a mainstay of home treatment for ingested poisons, is no longer recommended by the American Academy of Pediatrics. Ipecac’s efficacy in removing toxic substances from the stomach is limited and inconsistent and, therefore, not worth the severe vomiting and lethargy that sometimes result from its administration. If a child ingests a plant, mushroom, or medication whose level of toxicity is unknown to the caregiver, and calling a poison center is not an option, the child should be taken to a medical facility for evaluation.

Foreign Bodies

In addition to exploring the world around them with their mouths, toddlers and even young school-age children enjoy placing objects into their noses and ears. Such objects, particularly if they are organic in nature, can result in infection of the sinuses and external ear, respectively, and should be removed promptly.

Objects that are easily visible in the nose near the nares can be removed by two caregivers, one holding the child’s head motionless, while the other carefully removes the object with forceps or tweezers. If the object is not near the nares or cannot be easily visualized, a “mouth-to-mouth” technique can be used to try to remove the object. While occluding the uninvolved nare with one finger, the parent should place her mouth over the child’s mouth and blow hard several times. Ideally, this creates enough pressure to expel the object from the nasal passage. If an object is lodged in the child’s ear, it is best removed with forceful irrigation with clean, warm (37° C [99° F]) water using a bulb syringe. If the object is an insect, the ear should first be filled with isopropyl alcohol for several minutes to kill the insect prior to irrigation, unless there is a possibility that the tympanic membrane is perforated. If these techniques fail to remove the foreign body from the child’s ear or nose, the child should be brought to medical attention so that the object can be removed by direct visualization under proper procedural sedation.

Asthma

Parents of children with asthma face unique challenges when traveling into the wilderness or to the developing world. In both situations, access to medical care may be limited and parents may need to treat exacerbations that would normally require advanced medical attention. In addition, exposure to known asthma triggers, such as tobacco and specific allergens, may not be as controllable while traveling. A study of adult adventure travelers demonstrated that the major risk factors for asthma exacerbations while traveling include poorly controlled asthma prior to departure and intensive physical exertion.²⁶

To prepare for travel, parents should work with their pediatrician to stabilize their child’s asthma to the extent possible. Any physical exertion planned should be graded so that the child’s response can be gauged and activities scaled back as necessary. In locales with heavy particulate pollution or in settings with significant tobacco exposure, the child’s activities should be limited. In addition to packing extra canisters of the child’s inhalers and an extra spacer/aerochamber, parents should carry a course of high-dose steroids for administration during an acute exacerbation not responding immediately to an inhaled bronchodilator (e.g., albuterol). Options for steroids include prednisone or prednisolone (2 mg/kg on day 1, then 1 mg/kg on days 2 to 5 up to max 60 mg/day) or dexamethasone (0.6 mg/kg/day for 2 days up to max 10 mg/day). For children 5 years and older, a peak flow meter is a useful item to assist in gauging the severity of an asthma exacerbation. For families with children with life-threatening asthma (i.e., prior intubations), an EpiPen is an essential first-aid kit item.

Diabetes

Traveling with a child with diabetes requires thorough advance preparation and vigilance throughout the trip. Families traveling to the developing world or remote areas should assume that no supplies or medications will be available at their destination and should travel with sufficient insulin, syringes, alcohol wipes, lancets and test strips, and a spare glucometer. Urine test strips can also be extremely useful for parents trying to decide whether their child needs to be evacuated to medical care if traveling in a remote location. The presence of ketones in the urine in a diabetic child who is ill should mandate immediate medical evaluation. Parents should also prepare a list of medical providers and/or hospitals capable of providing medical assistance to their child should the need arise.

Diabetic children should be encouraged to drink fluids frequently, particularly at high altitude and in warm climates. Parents of diabetics should always carry glucose tablets and small snacks that they know their child will eat. Older children should carry these items for themselves. Daily trip planning should guarantee that meals and snacks are not skipped by a diabetic child. Parents should also be aware that with increased activity that occurs during travel, insulin dosing may need to be reduced to prevent hypoglycemia. Finally, diabetic children are at greater risk for infections, particularly those of the skin. All wounds should be thoroughly cleaned with soap and clean water. Any redness, warmth or edema should be treated with antibiotics, preferably trimethoprim (TMP)–sulfamethoxazole (8 to 10 mg/kg/day of the TMP component divided twice daily) to cover MRSA. Marine wounds and animal bites will require additional antibiotics (e.g., quinolones and amoxicillin–clavulanate, respectively) to cover specific organisms. Diabetic children with wounds that progress despite oral antibiotics should receive prompt medical evaluation.

Sickle Cell Disease

For children with sickle cell disease, the focus during travel should be on prevention. Parents should be aware of the triggers for pain crisis, and should emphasize good hydration and hygiene to prevent diarrheal illness. Travel to high altitude should, in general, be avoided, because of the possibility of altitude-related hypoxia resulting in a pain crisis. If a crisis develops, the child should be treated with rest, oral hydration, and appropriate pain medications (ibuprofen or narcotics). If this therapy is ineffective or if the crisis involves chest or abdominal pain, parents should seek immediate medical attention for their child.

Fever is a common and significant problem for children with sickle cell disease. By the age of 1 year, children with this disease are effectively asplenic as a result of sickling-related infarction of the spleen. As a consequence, infections with encapsulated organisms normally cleared by the spleen can rapidly lead to sepsis. Vaccinations against Haemophilus influenzae, Streptococcus pneumoniae, and Neisseria meningitidis (MCV4) are the first line of defense. In addition, the American Academy of Pediatrics recommends penicillin prophylaxis (125 mg twice a day) for sickle cell patients under the age of 5 years to effect a significant (85%) reduction in pneumococcal bacteremia.²⁴ Children with sickle cell disease who develop fever should receive prompt medical attention. If this is not immediately available, they should be treated with an antibiotic, such as amoxicillin–clavulanate (80 mg/kg/day divided twice daily). Children under the age of 5 years are at particularly high risk for sepsis.

Congenital Heart Disease and Pulmonary Hypertension

Traveling with children with cardiac or pulmonary problems can be a challenge. During flight, most airline cabins are pressurized to allow a fraction of inspired oxygen (FIO₂) of 0.17 or 0.18 as opposed to the typical FIO₂ of 0.21 at sea level. Depending on the nature and severity of the child’s disease, this may require arranging for an oxygen tank and delivery apparatus during flight. Travel to high altitude should be cleared by the child’s primary or specialty physician for the same reasons. Respiratory infections are also more common during travel. Because of the potentially significant impact of seemingly minor respiratory infections (e.g., influenza) on children with cardiopulmonary disease, hand hygiene is particularly important to prevent inoculation with infected secretions via hand-to-nose and hand-to-eye contact. An emergency plan should be available for every country on the child’s itinerary, including a specialist contact and a full description of the child’s condition and health care needs.