allergic reaction


Photoclinic: Neonatal Acne

For the past 10 days, a 3-week-old infant had a rash on the face. He was born at term to a healthy, 22-year-old primigravida, following an uncomplicated pregnancy and normal spontaneous vaginal delivery (birth weight, 3.1 kg; length, 49.5 cm). Numerous comedones and papules were noted on the infant's cheeks.

Alexander K. C. Leung, MD, and Justine H. S. Fong, MD, of Calgary, Alberta, diagnosed neonatal acne. Characteristically, this condition manifests within the first 2 to 3 weeks of life as erythematous comedones and papules, although pustules and nodules may also be seen. The lesions predominate on the cheeks and forehead. Neonatal acne likely results from the effects of androgens on sebaceous glands. This has been attributed to transplacental transfer of maternal androgens or hyperactive neonatal adrenal glands. In addition, there is a transient surge of gonadotropin shortly after birth that leads to a sharp increase in serum testosterone levels in the male neonate. Accordingly, neonatal acne is more common in boys (male-to-female ratio, 4 to 5:1).

Neonatal acne needs to be differentiated from erythema toxicum neonatorum, milia, miliaria rubra, transient neonatal pustular melanosis, infantile acropustulosis, staphylococcal folliculitis, and cephalic pustulosis caused by Malassezia species.1-4

Neonatal acne is self-limited. The lesions usually resolve spontaneously without scarring in 3 or 4 months, as was the case with this patient.