Cutaneous Mastocytosis: A Case of Bullous Urticaria Pigmentosa

Mastocytosis is characterized by an increased number of mast cells with abnormal growth and accumulation in 1 or more organs. In children, mastocytosis is commonly cutaneous and patients present with a spectrum of findings, ranging from solitary or multiple mastocytomas to urticaria pigmentosa (UP) or diffuse cutaneous mastocytosis (CM). We present a case of a 4-month-old infant with bullous UP.