Malabsorption and gastric hyperacidity in systemic mastocytosis. Results of cimetidine therapy.

Visceral infiltration by mast cells (systemic mastocytosis) is an unusual manifestation of cutaneous mastocytosis. Symptomatic gastrointestinal disease occurs in approximately one-fourth of patients having systemic mastocytosis. An unusual gastrointestinal complication is malabsorption, described in sporadic case reports. A patient with gastric acid hypersecretion and malabsorption is described. Treatment using the histamine H2 antagonist, cimetidine, ameliorated the patient's gastrointestinal symptoms; however, the malabsorption was not resolved.