Erythema Toxicum Neonatorum

ETN is usually not present at birth and normally develops on the third or fourth day of life. There are rare reports of its appearance anywhere from the first day of life through 2 weeks of age.
Lesions typically begin as ill-defined pink macules or edematous papules of variable size, that later develop 1- to 3-mm yellow to pale pink papules or pustules at the center.
Lesions are typically discrete and scattered and occur on the face, trunk, and extremities (Fig. 2.7).
The palms and soles are typically spared.
Rarely, the erythema may become confluent and widespread (Fig. 2.8).
Exacerbations and remissions can occur in the first 2 weeks of life.
The eruption usually self-resolves without sequelae over several days.

Management

It is important to first rule out an infectious etiology.
Parents can be reassured that this is a common, benign, asymptomatic, and self-limited condition.

Helpful Hint

Point to Remember

A Wright stain of pustule contents will show numerous eosinophils, but a Gram stain will be negative for bacterial organisms and a KOH will be negative for yeast.

Differential Diagnosis

Transient Neonatal Pustular Melanosis (see above)

Present at birth as flaccid vesiculopustules that rupture easily leaving behind a collarette of scale and a hyperpigmented macule.

Miliaria (see later in this chapter)

Occurs in first weeks of life secondary to heat and occlusion from excessive swaddling.
Presents as small pink to red papules, vesicles, or papulovesicles with an erythematous rim commonly grouped on the trunk.

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.