Nodular and bullous cutaneous mastocytosis of the xanthelasmoid type: case report.

Severe generalized nodular and bullous mastocytosis of the xanthelasmoid type is described in a 7-month-old boy. Reddish to yellowish-brown xanthelasmoid papules and nodules first developed in the inguinal region a few weeks after birth and then progressively spread to cover nearly the entire body surface. There was severe pruritus and recurrent episodes of blistering. The diagnosis of cutaneous mastocytosis of the xanthelasmoid type with subepidermal bullae was confirmed by skin biopsies showing solid and deeply penetrating infiltrates of metachromatic mast cells under light and electron microscopy. Systemic involvement of other organs, however, was excluded by bone scintigraphy, abdominal ultrasound, bone marrow aspiration and echocardiography. The extensive skin involvement was reflected in highly elevated urinary levels of histamine (263.4 microg L(-1)) and its metabolite N-methylimidazole acetic acid (20.8 mg L(-1)). The patient was systematically well and received only symptomatic treatment. Over a period of 1 year, the condition gradually improved, and the skin lesions began to flatten and regress.