• Affects approximately half of full-term neonates; less common in premature infants.

• Typically appears 1–2 days after delivery and lasts up to 1 week, with individual lesions resolving within 1 day; occasionally present at birth, and rarely develops as late as 1 to 2 weeks of age.

• Various combinations of erythematous macules, wheals, and small (≤2 mm) papules, pustules, and vesicles surrounded by a larger erythematous flare (Fig. 28.1); lesions may be grouped at sites of mechanical irritation.

• Often begins on the face and progresses to the trunk, buttocks, and proximal extremities; usually spares the palms and soles.

• Wright’s stain of pustular contents shows numerous eosinophils.

• Rx: none.

• Affects up to 5% of full-term neonates with darkly pigmented skin; less common in Caucasian newborns.

• Lesions are almost always present at birth.

• Three stages, any of which may be present at a given time (Fig. 28.2).

– 2- to 10-mm superficial vesiculopustules with little or no surrounding erythema.

– Collarettes of scale at sites of ruptured vesiculopustules.

– Residual brown macules representing post-inflammatory hyperpigmentation, which may persist for several months.

• Any region can be affected, but favors the forehead, chin, neck, lower back, and shins.

• Wright’s stain of pustular contents shows neutrophils > eosinophils.

• Rx: none.

• Common condition in newborns, especially with overheating related to excessive swaddling, warming in an incubator, fever, occlusive dressings, and hot climates.

• Caused by blockage of eccrine sweat ducts.

• Miliaria crystallina.

– Small clear vesicles (likened to ‘dew drops’) without surrounding erythema (Fig. 28.3); they are fragile and therefore short-lived.

– Most often on the forehead, upper trunk, and arms.

• Miliaria rubra.

– Usually develops at ≥1 week of age.

– Small erythematous papules, sometimes with a tiny central pustule or vesicle.

– Favors the neck, upper trunk, and occluded areas.

• Rx: avoid overheating and occlusion; bathing with lukewarm water.

• Affects ~20% of newborns.

• Onset usually at 2–3 weeks of life, with spontaneous resolution by 2–3 months of age.

• Papulopustular eruption on the face (cheeks > forehead, chin, eyelids) (Fig. 28.4) > neck, upper chest, and scalp.

• An absence of comedones in neonatal cephalic pustulosis distinguishes it from infantile acne, which typically develops at 3–12 months of age and is more persistent (see Chapter 29).

• May represent an inflammatory response to Malassezia spp., a normal component of the skin microbiome that may also trigger seborrheic dermatitis.

• Rx: usually not required; topical imidazoles (e.g. ketoconazole cream) may be helpful.

• Caused by habitual sucking of the affected area in utero, and resolves spontaneously within days to weeks of birth.

• Intact bulla, erosion, callus, or ulceration on a non-inflamed base.

• Common sites include the radial forearm, wrist, hand, and fingers.

• Congenital candidiasis.

– Uncommon condition that is acquired in utero; risk factors include maternal vaginal candidiasis, a foreign body in the uterus or cervix, and prematurity.

– Evident at birth or during the first few days of life.

– Findings range from erythematous papules and pustules with fine scaling in full-term neonates to diffuse, ‘burn-like’ erythema and erosions in premature infants (Fig. 28.5A,B).

– Often widespread involvement on the face, trunk, and extremities; the palms, soles, and nails (yellow discoloration, transverse ridging) are frequently affected, but the diaper area and oral mucosa are typically spared.

– DDx: budding yeast and pseudohyphae are seen in a potassium hydroxide preparation of skin scrapings, and culture grows Candida spp. (usually C. albicans).

– Rx: premature infants (especially if <1500 g) are at high risk for disseminated candidiasis and require systemic antifungal agents, as do full-term neonates with extracutaneous involvement (e.g. pneumonia); most full-term neonates have skin-limited disease that can be treated with topical antifungals (e.g. an imidazole cream).

• Neonatal candidiasis (see Chapter 64).

– Common condition that presents at ≥1 week of age as intense erythema with desquamation and satellite papulopustules, favoring the diaper area > other intertriginous sites (see Fig. 13.4); patients may also have oral thrush.

– Rx: topical imidazole or nystatin.

• Presents as early as a few days of age with flaccid bullae, vesiculopustules, and superficial shiny red erosions with collarettes of scale (Fig. 28.5C).

• Favors the diaper area and other intertriginous sites (see Fig. 13.4).

• DDx: Gram stain shows gram-positive cocci in clusters, and culture grows Staphylococcus aureus.

• Rx: topical antibiotic (e.g. mupirocin) for uncomplicated localized disease; systemic anti-staphylococcal antibiotic if more extensive (using an intravenous agent, e.g. vancomycin, if the patient is toxic appearing).

• Affects ~1 : 10 000 newborns in the United States; risk of transmission is highest (30–50%) for a mother with her first episode of genital HSV infection (which may be asymptomatic) near the time of delivery and low (<1–3%) for recurrent genital herpes.

• Onset from birth to 2 weeks, but usually ≥5 days of age.

• Localized (favoring the scalp and trunk) or disseminated vesicles (Fig. 28.6), pustules, and crusts; lesions are often grouped and may progress to bullae and erosions with scalloped borders.

• Involvement of the oral mucosa, eye, CNS, and other internal organs can occur.

• Rx: intravenous acyclovir.

• Onset often in the first few months of life, with cyclical recurrences for several months to years.

• Pruritic perifollicular pustules and crusts favoring the scalp (Fig. 28.7) and forehead.

• DDx: Erythema toxicum neonatorum (in neonates), bacterial folliculitis, tinea capitis, scabies, arthropod bite reactions.

• Rx: potent topical CS (intermittently for flares), oral antihistamines.

• Favors darkly pigmented male infants, sometimes representing a persistent hypersensitivity reaction following successful scabies treatment.

• Onset usually between 3 and 6 months of age; occasionally develops in newborns.

• Pruritic vesicles and pustules on the hands and feet (including palms/soles) (Fig. 28.8) > wrists and ankles.

• Outbreaks last 1–2 weeks, with cyclical recurrences until 2–3 years of age.

• DDx: scabies.

• Rx: potent topical CS (intermittently for flares), oral antihistamines.

• Multisystem X-linked disorder caused by mutations in the NEMO gene (NF-κB essential modulator); usually lethal in male fetuses.

• Typically presents in the first 2 weeks of life with vesicles on an inflammatory base in linear streaks that favor the extremities (Fig. 28.9); in subsequent weeks, verrucous streaks may develop, followed by more widespread linear and whorled grayish-brown hyperpigmentation.

• Extracutaneous findings in neonates with IP can include peripheral eosinophilia, leukocytosis, seizures, and retinal vascular abnormalities.