Clonal Mast Cell Disorders in Exercise-Induced Anaphylaxis

Anaphylaxis is a serious allergic reaction that develops rapidly and can cause death. Some
patients experience anaphylaxis is association with exercise, a disorder called
exercise-induced anaphylaxis. A subset of patients with unexplained anaphylaxis, especially
those with hypotension during the anaphylactic episodes, have been shown to have abnormal,
clonal populations of a certain cell type, mast cells, in the bone marrow. This has been
described in at least one patient with exercise-induced anaphylaxis. The investigators would
like review the findings in a group of patients with exercise-induced anaphylaxis who have
undergone evaluation for the presence of abnormal, clonal mast cells.