Bullous mastocytosis: report of a patient and a brief review of the literature.

We report a 6-month-old male infant who presented to the pediatric dermatology clinic at Wake Forest University Baptist Medical Center with a generalized bullous eruption since 3 months of age. A sepsis work up was performed at an outside hospital before presentation and did not reveal any evidence of systemic infection. Clinical presentation revealed a well-nourished, appropriate-for-age, 6-month-old boy with multiple tense bullae, some in a "string of pearls" arrangement, on the bilateral upper extremities and trunk. Multiple erosions were also noted. Laboratory evaluation revealed a normal complete blood count. Polymerase chain reaction was negative for herpes simplex virus types I and II. Histologic sections demonstrated a large space of separation between the epidermis and dermis which was filled by a monomorphous infiltrate composed of round to oval cells with centrally placed nuclei, consistent with mast cells. Leder and C-Kit stains were strongly positive, confirming the diagnosis of bullous mastocytosis. Treatment included fluocinonide 0.05% cream and tacrolimus 0.1% ointment to active lesions and silver sulfadiazine 1% cream to erosions. Improvement was noted during follow-up examination.