Pediatric Dermatology: Age-Specific Patterns and Vascular Anomalies
Think in developmental time
Pediatric dermatology questions often hinge on age at onset. Transient neonatal eruptions include erythema toxicum, milia, and neonatal sebaceous hyperplasia; neonatal acne appears in the first weeks, while cephalic pustulosis is a related papulopustular eruption. Atopic dermatitis follows an age-related distribution: cheeks and extensor surfaces in infancy, flexures in childhood. Diaper dermatitis has irritant, candidal, and seborrheic patterns; consider zinc deficiency or abuse when the pattern is atypical.
Vascular anomalies
Distinguish infantile hemangioma from vascular malformations. Infantile hemangioma typically appears after birth, proliferates in the first months, and involutes over years. Port-wine stains are present at birth and do not involute. Problematic hemangiomas-airway, vision, ulceration, or large segmental lesions-may require propranolol. Midline lumbosacral marks, dimples, or hair tufts can signal spinal dysraphism.
Genodermatoses and systemic clues
Know café-au-lait macules and neurofibromatosis, ash-leaf spots and tuberous sclerosis, and the streaks of incontinentia pigmenti. Fever, conjunctivitis, mucosal changes, and extremity changes suggest Kawasaki disease. Bullous impetigo and scabies are common mimics of other eruptions.
Worked rule
A “birthmark” that is absent at birth and grows rapidly in the first weeks is likely an infantile hemangioma, not a malformation. A vascular stain present at birth and proportional to growth is likely a malformation. Refer urgently for airway, ocular, or ulcerated hemangiomas.