Pediatric Dermatology

NEONATAL DERMATOLOGY
Transient Neonatal Pustular Melanosis (Figure 2.1A)

• Onset at birth; common in darkly pigmented infants
• Presents with small pustules or residual hyperpigmented macules with collarette of scale
• Smear of sterile pustule shows numerous neutrophils
• Histology: subcorneal pustules with neutrophils

Erythema Toxicum Neonatorum

• Onset typically 24 – 48 h after birth; occurs in half of all full-term infants
• Presents with blotchy erythematous macules, papules, pustules, and wheals
• Smear of sterile vesicle/pustule shows eosinophils
• Histology: subcorneal pustules with eosinophils, associated with pilosebaceous unit

Neonatal Cephalic Pustulosis (Neonatal Acne) (Figure 2.1B)

• Onset typically within first 30 days; Malassezia spp. implicated in pathogenesis
• Presents with erythematous follicular comedones, papules, and pustules on face
• Histology: follicular pustules with neutrophils

Sclerema Neonatorum

• Onset usually within first week of life; form of panniculitis in severely ill, premature infants; often fatal
• Presents with diffuse woody hardening of skin; spares genitalia, palms, and soles
• Histology: needle-shaped clefts with necrotic adipocytes with little surrounding inflammation

Subcutaneous Fat Necrosis of the Newborn (Figure 2.1C)

• Onset within first weeks of life; localized form of sclerema neonatorum in healthy infants
• Presents with indurated subcutaneous nodules favoring cheeks, shoulders, back, buttocks, and thighs
• Associated with hypothermia, perinatal hypoxemia (from preeclampsia, meconium aspiration, etc.), hypoglycemia
• Calcification may occur; ± profound hypercalcemia with resolution, so prudent to monitor calcium levels until 1 month after full resolution of lesions
• Histology: panniculitis with prominent inflammatory infiltrate, needle-shaped clefts and fat necrosis

Pedal Papules of Infancy

• Soft, non-painful papules involving heels

Seborrheic Dermatitis (Figure 2.2A)

• Onset typically 1 week after birth; lasts several months, mostly resolves by 1 year of age
• Presents with ill-defined erythematous patches with waxy scale over scalp (“cradle cap”), ± axillae and groin; lesions may appear psoriasiform

Miliaria Crystallina (MC) or Miliaria Rubra (MR)

• Onset within first few weeks of life; due to obstructed sweat glands and associated with ↑ temperature (i.e., occlusion)
• Presents with clear vesicles favoring head, neck, and upper trunk (MC) or erythematous papules/vesicles grouped in intertriginous areas or occluded areas (MR)

Aplasia Cutis Congenita (ACC) (Figure 2.2B, C)

• Onset before birth; localized defect in epidermis, dermis and/or fat; variable appearance, typically along midline
• Presents with erosion, ulceration, scar, or membranous defect (ovoid lesion covered by an epithelial membrane)
• Hair collar sign: ring of dark long hair encircling lesion; ± marker of underlying neural tube defect
• Typically isolated abnormality, but may be associated with developmental anomalies or following disorders:

Bart Syndrome ACC of lower extremities + epidermolysis bullosa (dominant dystrophic)   Adams–Oliver Syndrome ACC on scalp (with skull ossification defect) + extensive CMTC + limb defects (reductions, syndactyly) + cardiac abnormalities   Seitles Syndrome Bilateral temporal ACC + abnormal eyelashes, “leonine” facies, upward-slanting eyebrows

Cutis Marmorata Telangiectatica Congenita (CMTC)

• Onset at birth; typically improves with age
• Presents with blanching reticulated vascular pattern on trunk/extremities with segmental distribution
• Associated anomalies in ½ of patients (varicosities, nevus flammeus, macrocephaly, ulceration, hypoplasia, and/or hypertrophy of soft tissue and bone)

Sucking Blister

• Onset at birth or soon after; due to sucking
• Presents with solitary blister (hand, wrist, or lip)

Congenital Infections of the Newborn (see Table 2-1)

Table 2-1 Congenital Infections of the Newborn   Infection Clinical Findings Extracutaneous Findings Important Points   Cytomegalovirus (CMV) Petechiae, purpura, vesicles, and “blueberry muffin” lesions (Blueberry muffin lesions: red-blue papules/nodules due to dermal erythropoiesis) Intrauterine growth retardation, chorioretinitis, intracranial calcification ⇒ Leading infectious cause of deafness and mental retardation ⇒ Typical findings on histology: enlarged endothelial cells with intranuclear inclusions   Herpes Simplex Virus (HSV) Localized or disseminated skin lesions (vesicles, erosions, scarring) Encephalitis (predilection for temporal lobes), multi-organ failure, ocular infection ⇒ Majority HSV2, 85% acquired perinatally ⇒50–75% mortality if left untreated   Rubella “Blueberry muffin” lesions Cataracts, deafness, congenital heart disease, CNS findings (microcephaly, hydrocephaly), hepatosplenomegaly (HSM) ⇒ 50% chance of deafness ⇒ Severe birth defects if within first 16 weeks of pregnancy ⇒ Non-immune pregnant woman transfer the virus to the fetus   Toxoplasmosis “Blueberry muffin” lesions favoring the trunk Ocular abnormalities (chorioretinitis, blindness), CNS abnormalities (deafness, mental retardation, seizures), thrombocytopenia, intracranial calcification   Varicella Cicatricial skin lesions Ocular abnormalities (chorioretinitis, cataracts), cortical atrophy, psychomotor retardation, hypoplastic limbs ⇒ Greatest risk in first 20 weeks ⇒ 2% risk of embryopathy in women with infection within first two trimesters   Syphilis, Early Congenital Syphilitic pemphigus, rhagades (radial furrows/fissures in perioral area, turn into parrot lines), papulosquamous macules/papules (like secondary syphilis) Snuffles (rhinitis, secondary to ulcerated mucosa), enlarged lymph nodes and spleen, neurosyphilis (Be able to differentiate early and late congenital syphilis findings) ⇒ Early congenital syphilis occurs from birth to 2 years of age ⇒ Only congenital syphilis may show bullous lesions ⇒ Papulosquamous lesions common in the diaper area   Syphilis, Late Congenital Hutchinson’s teeth, Higoumenakis sign, mulberry molars, saddle nose, saber shins, parrot lines and furrows Interstitial keratitis, gummas along long bones/skull, tabes dorsalis, generalized paresis ⇒ Includes permanent sequelae of early congenital signs ⇒ Higoumenakis sign: congenital thickening of the medial aspect of the clavicle

Differential Diagnosis of ‘Diaper Dermatitis’ (see Table 2-2)

Table 2-2 Differential Diagnosis for Diaper Dermatitis   Entity   Clinical Findings   Candidal Dermatitis Bright red patches with pustules and satellite papules, ± intertriginous involvement (including scrotum), ± thrush   Irritant Dermatitis Poorly demarcated erythematous plaques, spares inguinal folds   Seborrheic Dermatitis Typical salmon-covered scaly patches and plaques involving the scalp, groin, and other intertriginous areas   Psoriasis Sharply demarcated bright pink to red plaques involving inguinal creases, minimal scale; most common psoriatic presentation in infants   Allergic Contact Dermatitis Rare in infants, ± related to topical preparations or foods   Atopic Dermatitis Increased incidence of diaper dermatitis in atopic patients   Miliaria Clear vesicles or erythematous papules/pustules due to blocked eccrine ducts from heat or humidity in diaper area   Granuloma Gluteale Infantum Red to violaceous granulomatous nodules over the vulva, perianal area, buttocks, ± scrotum; due to irritation, occlusion, candidal infection   Perianal Pseudoverrucous Nodules Erythematous nodules and papules in children with fecal incontinence   Acrodermatitis Enteropathica Erythematous crusted patches/plaques with flaccid bullae in perineal, periorificial, and distal extremities; due to ↓ zinc level (also ↓ alkaline phosphatase as zinc-dependent); may occur in following settings:   Premature infants (poor absorption and ↑ requirement of zinc) when weaned off breast milk (which has adequate zinc level) Inherited form (AR) manifests when weaned off breast milk Healthy infants if low zinc level in maternal milk Acquired form if malabsorption or inadequate nutrition   Cystic Fibrosis Resembles acrodermatitis enteropathica, also due to zinc deficiency ± pedal edema, failure to thrive, infections and malabsorption   Multiple Carboxylase Deficiency Both resemble acrodermatitis enteropathica (periorificial dermatitis); treatment for both forms (listed below) is biotin   Biotin Deficiency Neonatal form: AR, holocarboxylase synthetase deficiency, ± erythroderma with alopecia, fatal if not treated Juvenile form: biotinidase deficiency, ± seizures, alopecia, hearing loss, developmental delay   Langerhans Cell Histiocytosis Yellow-brown crusted papules with purpura in seborrheic distribution; ± systemic involvement; Langerhans cells (CD1a +, S100+)   Kawasaki Disease Tender erythema in perineal area which later desquamates   Perianal Strep Bright red, well-demarcated perianal erythema and involving creases   Bullous Impetigo Honey-colored crusts and flaccid bullae   Scabies Erythematous nodules involving diaper area, ± genitalia   Congenital Syphilis Reddish-brown papulosquamous eruption, may be erosive or bullous