IgE mediated anaphylaxis in a patient with systemic mastocytosis

Background. - Anaphylaxis is a severe, generalized, life-threatening reaction of rapid onset. We report the case of a patient presenting several systemic anaphylactic reactions over many years, initially ascribed to a cereals allergy but which finally proved to be due to systemic mastocytosis hidden for a long time. Patients and methods. - A 53-year-old man consulted for an eruption consisting of monomorphic pigmented maculopapular lesions on the trunk associated with itching and urticaria. He was a farmer and presented severe sensitivity to cereals, with anaphylaxis, which continued despite withdrawal of these allergens. Skin and bone marrow infiltration, abnormal mast cells, positivity for c-kit 816 mutation and the persistent elevation of serum tryptase enabled a diagnosis of indolent systemic mastocytosis to be made. Discussion. - In systemic mastocytosis anaphylaxis is an expected complication relating to the proliferation of mast cells and a massive increase in mediator release (non-immunological mechanism). All patients with severe and recurrent anaphylaxis should be analyzed for underlying mastocytosis by careful physical examination and assay of baseline tryptase. (C) 2013 Elsevier Masson SAS. All rights reserved.