Chapter 47 Kawasaki Disease
PATHOPHYSIOLOGY
Kawasaki disease is an acute, self-limited vasculitic syndrome affecting infants and young children. Kawasaki disease is distinguished by marked immune system activation that contributes to the injury of small- and medium-sized blood vessels, with a predilection for the coronary arteries. Also known as mucocutaneous lymph node syndrome, Kawasaki disease affects multiple body systems and can have life-threatening cardiovascular consequences, including thrombosis of coronary arteries, coronary artery aneurysms, and coronary stenosis. Researchers speculate that Kawasaki disease has an infectious cause; however, the specific etiology remains unknown. The disease occurs in three phases; acute febrile, subacute, and late or convalescent. Diagnosis, which is sometimes confusing, has been based on strict adherence to clinical criteria. However, a substantial subset of children present with illnesses that do not completely fulfill the diagnostic criteria and are associated with the coronary diseases similar to that of the typical Kawasaki disease. These cases are labeled “atypical Kawasaki disease.” Initial treatment focuses on reducing the vascular inflammatory process. With early recognition and treatment, prognosis is excellent. The long-term prognosis for children with coronary artery abnormalities who survive the disease is unknown, but recent surveys suggest that the sequelae of Kawasaki disease are likely important causes of ischemic heart disease in young adults.
INCIDENCE
1. Of all children with diagnosed Kawasaki disease, 80% are 5 years of age or younger, with toddlers most commonly affected (50% are younger than 2 years of age).
2. In the United States the peak age for being diagnosed with Kawasaki disease is 18 months.
3. Adults, adolescents, and children less than 6 months of age are rarely affected.
4. Outbreaks of Kawasaki disease are more common in the late winter and early spring but can be seen at any time during the year.
5. Annual incidence in the United States is 5.6 per 100,000 individuals as compared to 67 per 100,000 individuals in Japan.
6. The incidence is higher in boys than in girls (1.5:1). Boys have a higher ratio of fatalities due to Kawasaki disease.
7. The disease occurs in all races but has a higher predilection for Japanese children, followed by Asian and Pacific Islanders, African Americans, Hispanics and, finally, is at its lowest incidence in whites.
8. Kawasaki disease occurs more often in twins and siblings than in the general population.
9. No evidence exists to suggest that Kawasaki disease is spread by person-to-person contact.
10. The increased rates of occurrence in family members suggest there may be a genetic predisposition to Kawasaki disease.
11. Of untreated children with Kawasaki disease, 15% to 20% develop coronary artery aneurysms.
12. Of those children treated with intravenous gamma globulin (IVIG) in the acute phase of the disease, fewer than 5% develop coronary artery abnormalities.
CLINICAL MANIFESTATIONS
Acute Febrile Phase (0 to 19 Days)
For Kawasaki disease to be diagnosed, the child must have a fever for 5 days and four of the following acute phase criteria:
1. Fever is abrupt in onset, typically high (39° to 40° C), spiking, and remittent. If left untreated, the fever may persist for 11 days on the average. The fever is present in 95% of children with Kawasaki disease.
2. Bulbar conjunctivitis is seen in the first few days of the illness, occurring shortly after the first fever. It is usually painless and not associated with exudate or edema.
3. Oropharyngeal manifestations include changes in the mouth and lips including erythema, dryness, fissuring, peeling, cracking, and bleeding of the lips; a “strawberry tongue”; and diffuse erythema of the oropharyngeal mucosa (nonexudative and nonulcerative).
4. Extremity changes include swelling and induration of the hands and feet, erythema of the palms and soles, and painful extremities; often, children no longer bear weight. The skin becomes shiny and stretched in appearance.
5. Erythematous body rash usually appears within 5 days of fever and may take many forms. Most commonly the rash is a nonspecific, diffuse, maculopapular eruption. The rash is most extensive to the trunk but can involve the face and extremities. The rash in the perineal area is accentuated, and early desquamation may occur.
6. Cervical lymphadenopathy is the least common of the criteria; it is usually unilateral and located in the anterior cervical triangle. The enlarged node is usually greater than 1.5 cm in diameter, nonfluctuant, and nontender.
7. Cardiac abnormalities include myocarditis, arrhythmias, hyperdynamic precordium, tachycardia, gallop rhythm, depressed myocardial contractility, mitral regurgitation, and coronary artery abnormalities.
Subacute Phase (12 to 25 Days)
1. Arthritis frequently includes multiple joints, most commonly large weight-bearing joints
3. Thick desquamation of the extremities, starting at the tip of the digits and progressing proximally
4. Panvasculitis of coronary arteries and formation of aneurysms; inflammation and thrombosis may lead to stenosis or obstruction
Convalescent Phase (6 to 8 Weeks)
1. Subsidence of the signs of illness
2. Appearance of deep linear transverse grooves across the fingernails and toenails (Beau’s lines), which may progress to complete shedding of the nails
3. Abnormal laboratory values begin returning to normal
4. Normalization of personality, irritability, appetite, and energy level
COMPLICATIONS
LABORATORY AND DIAGNOSTIC TESTS
Refer to Appendix D for normal values and/or ranges of laboratory and diagnostic tests.
There are no specific diagnostic tests for Kawasaki disease; however, several abnormalities have been identified.
1. Electrocardiogram (ECG)—to assess electrical conduction of the myocardium
2. Echocardiogram—to assess cardiac enlargement, contractility of ventricles, and coronary aneurysms
3. Complete blood count—to assess for suggestive indices of Kawasaki disease
4. Acute phase reactant elevation—to assess inflammatory processes
5. Liver function studies—to assess involvement of liver function
6. Serum lactic dehydrogenase level (LDH)—elevated during acute febrile phase and decreased during convalescent phase (LDH levels are nonspecific, but elevation is an early indicator of cellular death in the myocardium)
7. Immunoglobulin E and immunoglobulin M—to assess immune response during illness; elevation is observed during acute febrile phase and decreased during convalescent phase
8. Complement levels (C3 and C4)—to assess immune response; is increased in the first several weeks of the illness
9. Urinalysis may reveal a sterile pyuria
10. Cerebrospinal fluid may reveal aseptic meningitis with a predominance of mononuclear cells with normal protein and glucose
MEDICAL MANAGEMENT
Initial therapy is aimed at reducing the vascular inflammatory process and preventing thrombosis by inhibiting platelet aggregation. IVIG has made a tremendous difference to the treatment of Kawasaki disease. If given within 10 days from the onset of symptoms, IVIG significantly shortens the disease duration and minimizes complications. IVIG is given as a 2 g/kg infusion delivered over 10 to 12 hours, ideally within the first 7 days of the illness. The mechanism of action of IVIG is unknown, but it appears to have an antiinflammatory effect, which decreases the inflammation of the coronary arteries and speeds the resolution of the fever. IVIG may be repeated at the same dose for a second infusion if the fever persists longer than 36 hours after the first infusion.
Aspirin therapy has been used for years in Kawasaki disease. Aspirin is used in the acute phase for its antiinflammatory effect as well as for its antithrombotic effect. The dosing is divided into two different phases. During the initial phase, aspirin is given at 80 to 100 mg/kg/day in four divided doses. High-dose aspirin should be initiated as soon as Kawasaki disease is suspected and given until the child remains afebrile for 48 to 72 hours. After the resolution of the fever, the dose of aspirin is decreased to 3 to 5 mg/kg/day in a single daily dose for 6 to 8 weeks. After 6 to 8 weeks, if the echocardiogram is normal, the aspirin is discontinued. If the echocardiogram reveals coronary artery abnormalities, low-dose aspirin therapy (3 to 5 mg/kg/day) is continued indefinitely.
The use of corticosteroids is controversial, but may be used in children refractory to IVIG therapy. Warfarin (Coumadin) is sometimes used in children who have developed giant aneurysms. The international normalized ratio (INR) should be maintained between 2 to 2.5 while the child receives warfarin. Furosemide (Lasix) may be used in patients with congestive heart failure. Plasma exchange has been reported to be effective in treatment-refractory children in uncontrolled clinical trials.
NURSING ASSESSMENT
1. See the Cardiovascular Assessment section in Appendix A.
2. Assess skin for color, moisture, texture, turgor, rashes, lesions, and integrity.
3. Assess for clinical criteria of Kawasaki disease.
4. Assess for febrile seizures.
5. Assess adequacy of hydration.
NURSING DIAGNOSES
NURSING INTERVENTIONS
1. Monitor child’s clinical status.
2. Institute measures to lower fever.
3. Monitor child for cardiac complications.
4. Monitor for untoward signs and symptoms (hypotension, diaphoresis, nausea and vomiting, chills) during IVIG administration, and stop infusion until symptoms have subsided. Keep epinephrine available to treat anaphylaxis.
5. Monitor for signs of bleeding due to aspirin or anticoagulant therapy.
6. Provide comfort measures for child.
7. Provide for and promote child’s nutrition.
8. Prevent contractions related to imposed restrictions and range of motion (ROM) limitations.
9. Alleviate anxiety caused by invasive procedures for diagnostic tests and by pain, new environment, strange people, knowledge deficit, and age-related fears (refer to Appendixes B and C).
Discharge Planning and Home Care
Instruct about long-term management.
1. Instruct parents and child, in developmentally appropriate manner, about importance of follow-up care including ECGs, echocardiograms, and chest radiographic studies (two thirds of coronary aneurysms regress within 1 year).
2. Instruct parents verbally and with written reinforcement about signs and symptoms of cardiac complications (i.e., aneurysms and coronary thromboses); tell them to contact health care provider immediately if child has any of these signs and symptoms.
3. Instruct parents about importance of anticoagulant therapy such as aspirin and about side effects to watch for; explain to parents why some children with Kawasaki disease may need to undergo coronary artery bypass grafting.
4. Instruct parents about importance of good nutrition and adequate fluid intake.
5. Stress importance of adequate rest.
6. Educate parents about delaying administration of live virus vaccines (such as measles, varicella) for 11 months after child receives IVIG.
7. Avoid high-impact sports or activities while on anticoagulant therapy.
8. Instruct parents to have child checked for cardiovascular factors every 5 years.
9. Instruct parents to seek medical care immediately for flulike symptoms while on aspirin therapy.
CLIENT OUTCOMES
1. Child’s temperature will return to normal.
2. Changes in skin will resolve.
3. Child will walk without joint pain.
4. Child will remain hemodynamically stable.
5. Child will remain free of nosocomial infections.
6. Child will resume age-appropriate activities.
7. Child will feel a sense of mastery about the illness experience.
Nasr I, Tometzki AJP, Schofield OM. Kawasaki disease: An update. Clin Exper Dermatol. 2001;26:6.
Newburger JW, et al. Diagnosis, treatment, and long-term management of Kawasaki disease: A statement for health professionals from the committtee on rheumatic fever, endocarditis, and Kawasaki disease council on cardiovascular disease in the young, American Heart Association. Pediatrics. 2004;114(6):1708.
Shulman S. Kawasaki disease. Feigen RD, et al. Textbook of pediatric infectious disease, ed 5, Philadelphia: WB Saunders, 2004.
Shulman ST, Rowley AH. Advances in Kawasaki disease. Eur J Pediatr. 2004;163:285.
Yamamoto LG. Kawasaki disease. Pediatr Emerg Care. 2003;19(6):422.
