Pediatric Dermatology: Developmental Rashes and Vascular Anomalies
Neonatal and infant skin
Pediatric dermatology emphasizes developmental change. Newborn rashes are usually benign: erythema toxicum neonatorum (blotchy erythema with eosinophilic pustules), transient neonatal pustular melanosis (pustules with collarette scale), and milia. Trap: grouped vesicles in a neonate suggest herpes simplex and require urgent evaluation, not a diaper rash label.
Vascular anomalies are high-yield. Infantile hemangiomas appear in the first weeks, proliferate for months, and involute; complications include ulceration and airway obstruction. Port-wine stains are present at birth, do not regress, and facial distribution may signal Sturge-Weber syndrome (V1, ocular, CNS). Rule of thumb: a segmental facial port-wine stain requires ophthalmologic and neurologic assessment.
Atopic dermatitis is the most common pediatric dermatosis; look for flexural involvement, sparing of the diaper area, and associated asthma or allergic rhinitis. Seborrheic dermatitis favors the scalp and diaper creases and responds to mild cleansing. Tinea capitis causes alopecia with scale and broken hairs; KOH or fungal culture is required, and oral therapy is standard because topical agents fail.
Traps: molluscum contagiosum is self-limited, so aggressive destructive therapy is inappropriate; diaper dermatitis that spares creases suggests irritant contact dermatitis, while crease involvement suggests candidiasis. Cutaneous signs of child abuse - patterned bruises, cigarette burns, and injuries in nonmobile infants - must be recognized.
Worked example: a 6-week-old with a growing red nodule on the lip. This is an infantile hemangioma; because of feeding and airway risk, early referral for beta-blocker therapy is indicated.