Hypereosinophilic syndrome: case presentation and update.

Persistent peripheral blood eosinophilia can be associated with a variety of diseases, ranging from parasitic infection to gastrointestinal disease to vasculitis to the hypereosinophilic syndrome (HES). Mucosal ulcerations are a variant presentation of the HES that appear to be markers for a mutation that characterizes a subgroup of patients with HES responsive to treatment with imatinib mesylate. We present a patient with peripheral blood eosinophilia and severe recurrent mucosal ulcers and discuss his presentation in the context of new information about the evaluation, disease progression, and treatment of HES.