Erythema toxicum neonatorum
* Synonyms: Toxic erythema of the newborn, Erythema toxicum.
* Importance:
1. Common condition affects as many as half of all full-term newborn infants.
2. Many differential diagnoses in early infantile life with similar rash.
3. Characteristic histological picture.
* Onset: First few days after birth (usually second or third day of life), although onset can be as late as two weeks of age.
* Aetiology: Unknown.
* Presentation: Combinations of erythematous macules, red patches, papules and pustules. There may be confluent erythema on the face.
The general condition of the infant is usually well (no fever).
Sites: Often begins on the face and spreads to affect the trunk and limbs. Palms and soles are not usually affected.
* Course: Typically waxes and wanes over several days and the eruption
generally disappears by the 10th day.
* Diagnosis: Primarily clinically based. In atypical cases smears of the pustules demonstrating eosinophils are adequate to confirm the diagnosis.
* Histopathology: diffuse infiltrate of eosinophils and neutrophils in the upper dermis. Papules shows an eosinophilic infiltration around the hair follicle.
Pustular lesions show perifollicular subcorneal pustules filled predominantly with eosinophils.
* DDX: The most important are:
1. Infections (folliculitis, impetigo, congenital cutaneous candidiasis, herpes simplex, varicella and CMV).
2. Miliaria (rubra and pustulosa).
3. Eosinophilic pustulosis (infantile Ofuji syndrome).
4.Transient pustular melanosis, and
Treatment: Not required (Benign self-healing condition).