Bullous mastocytosis treated with oral betamethasone therapy.

Bullous mastocytosis is a very rare variant of cutaneous mastocytosis. The condition is characterized by a diffuse infiltration of the skin by mast cells manifesting as yellowish, thickened doughy skin with appearance of large blisters. The authors report herewith a 7-month-old female infant with history of recurrent episodes of vesiculobullous lesions on the face, trunk and the extremities and excessive tendency to rub and scratch the skin for 3 months. She also had recurrent episodes of facial flushing. On cutaneous examination there were multiple flaccid bullae, urticarial wheals and crusted erosions on her scalp, face, neck, trunk and extremities. She had generalised yellowish thick and rough skin, giving doughy feel and 'peau d' orange' appearance of the skin at places. Systemic examination was within normal limits. Skin biopsy from a lesion showed subepidermal bulla and an upper dermal inflammatory infiltrate comprising of lymphocytes and many mast cells. Toluidine blue staining of the cells showed presence of metachromatic granules in these cells. A diagnosis of bullous mastocytosis was made and the patient was treated with oral antihistamines to which there was no satisfactory response. Betamethasone in a dose of 0.1 mg/kg/day given orally caused complete remission of the disease in 4 weeks. The drug was gradually tapered and stopped over the next 6 weeks. There were no side effects of the therapy.