Myiasis due to Hypoderma lineatum infection mimicking the hypereosinophilic syndrome

Myiasis is the infestation of live humans with larvae of Diptera (true flie s). This report describes a protracted illness caused by infestation with H ypoderma lineatum, resembling the hypereosinophilic syndrome. A 35-year-old man had a 9-month multisystemic illness with pronounced eosinophilia, pleu ritis, pericarditis, and myositis, Treatments including glucocorticoids did not alter the disease. Diagnostic studies included computed tomography, 2- dimensional echocardiography, leukocyte count surgical biopsy of skin and m uscle, blood immunoglobulin levels, and blood chemistry. Myiasis was recogn ized when a worm emerged from the patient's skin; after a second worm emerg ed, the patient's symptoms disappeared rapidly. Other determinations includ ed IgE and IgG levels specific for H lineatum, Western blot, and immunofluo rescence for eosinophil major basic protein; IgG antibodies to H lineatum d ecreased after emergence of the worms. The patient's symptoms mimicked the hypereosinophilic syndrome but resolved when the myiasis became apparent. S pecific serologic analyses can identify infected patients, and ivermectin m ay be useful as treatment.