Phototherapy-Induced Yellow Urticaria in a Neonate.

Yellow urticaria is a rare variant of urticaria typically associated with liver disease with elevated bilirubin levels in adults. It has never been reported in a neonate or as a reaction to phototherapy. We present the case of a 3-day-old male newborn treated with phototherapy for neonatal jaundice due to Rhesus incompatibility, who developed transient yellowish papules confined to light-exposed areas. These lesions were diagnosed as phototherapy-induced yellow urticaria. This case highlights a unique cutaneous reaction to a commonly used treatment in neonatology.