A case of systemic mastocytosis; therapeutic efficacy of ketotifen.

A 68-year-old man presented with a 6-month history of fatigue, rhinorrhoea, pruritic skin lesions, left pleural effusion, ascites, oedema and weight loss of 10 kg. Investigations revealed hepatosplenomegaly, retroperitoneal lymphadenopathy, anaemia, leucocytosis with eosinophilia, hypoprothrombinaemia, hypocholesterolaemia and elevation of both gamma glutamyltransferase and alkaline phosphatase. Biopsies of a skin lesion, bone marrow and liver revealed mast cell infiltration, allowing the diagnosis of systemic mastocytosis (SM). Hydroxyzine plus ranitidine were given without success. Hydroxyzine treatment was stopped, and ketotifen was initiated; substantial symptomatic improvement was observed within 8 d. This case report indicates the effectiveness of ketotifen in the symptomatic treatment of SM.