Pediatric Dermatology and Genodermatoses
Age changes the differential
Many diseases look different in children. Neonatal and infant skin findings are frequently benign and transient, while genodermatoses require recognizing patterns across organ systems.
Concepts to master
- Neonatal findings: erythema toxicum neonatorum (blotchy erythema with pustules), transient neonatal pustular melanosis (pustules with collarette scale and hyperpigmented macules), and milia.
- Atopic dermatitis: infantile (face and extensor surfaces), childhood (flexural), and adult patterns.
- Hemangiomas and vascular anomalies: infantile hemangioma grows then involutes; port-wine stain is present at birth and does not involute.
- Genodermatoses: neurofibromatosis type 1 (café-au-lait macules, axillary freckling, neurofibromas), tuberous sclerosis (ash-leaf macules, facial angiofibromas, shagreen patch), and incontinentia pigmenti (Blaschkoid vesicular, verrucous, and pigmented stages).
- Kawasaki disease: fever, mucositis, polymorphous rash, extremity changes, and cervical lymphadenopathy; risk of coronary aneurysm.
Traps
Do not mistake benign neonatal pustular eruptions for infection - the infant is well and the lesions are transient. Do not call a port-wine stain a hemangioma; the former is present at birth and requires evaluation for Sturge-Weber syndrome when in the V1 distribution. In Kawasaki disease, the rash is nonspecific but the clinical criteria and cardiac risk drive management.
Worked example
A febrile child with cracked lips, strawberry tongue, conjunctival injection, and a polymorphous rash. Diagnosis: Kawasaki disease. The priority is echocardiography and timely intravenous immunoglobulin to prevent coronary artery aneurysms.