Transient Neonatal Pustular Melanosis

Lesions are typically evident at birth and evolve through three phases:
- Phase 1: Flaccid vesiculopustules with minimal to no erythema, last 24 to 48 hours (Fig. 2.4).
- Phase 2: Collarettes of scale (representing ruptured vesicles) (Fig. 2.5).
- Phase 3: Hyperpigmented macules, resolve over weeks to months (Fig. 2.6).
Phases 1 and 2 can happen in utero and baby is born with only brown “freckle-like” macules, or baby can be born with a combination of pustules, collarettes of scale, and hyperpigmented macules.
Any site can be affected but lesions have a predilection for forehead, chin, neck, lower back, and diaper area.
Rarely, may be seen on the scalp, palms, and soles.

Diagnosis is based on clinical recognition.
A Wright stain of pustule fluid will demonstrate neutrophils and solidify the diagnosis.
KOH, Gram stain, and Tzanck smear will be negative.

Differential Diagnosis

Bullous Impetigo

Superficial flaccid pustules and bullae typically found in the diaper area, axillae, or sites of wounds (circumcision or umbilical cord).
Gram stain will reveal gram-positive cocci.

Erythema Toxicum Neonatorum (see below)

Congenital Candidiasis

Tiny pustules or collarettes of scale on an erythematous base.
When present at birth is usually widespread and often present on palms and soles.
KOH of pustule contents will reveal pseudohyphae and budding yeast.

Café au Lait Spots

Variably sized well-demarcated tan patches that present at birth as 1 to 3 discrete lesions.
Persist unchanged over time.

Management

TNPM should be distinguished from a congenital skin infection.
Reassure parents of complete spontaneous resolution within the first weeks of life.
Hyperpigmented macules may take several months to fade completely.

Point to Remember

In TNPM, a Wright stain of pustule fluid will show many neutrophils but a Gram stain will be negative for bacterial organisms.