Eosinophil cationic protein in a 39-year-old patient with Churg-Strauss syndrome

A 39-year-old woman in good health suddenly developed painful paraesthesia and incomplete paresis of all four limbs. Furthermore, arterial hypertension and tachycardia were found. The patient reported a history of chronic allergic rhinitis for 10 years and asthma one year. Laboratory data showed an increased leucocyte count with a substantial increase in eosinophils in peripheral blood as well as in bone marrow. Nonspecific inflammatory markers such as erythrocyte sedimentation rate, C-reactive protein, fibrinogen as well as eosinophil cationic protein (ECP) were also increased. Histological investigations of a skin-muscle biopsy of the quadriceps revealed necrotizing vasculitis with extravascular granulomata and histiocytic giant cells. Based on the diagnosis of Churg-Strauss syndrome treatment with methylprednisolone (500 mg every second day) was started, but was found to be ineffective after 10 days. Symptoms responded well to a subsequent course of 150 mg cyclophosphamide combined with 50 mg prednisolone per day. Pareses and pain were significantly reduced and all qualitative nerve functions returned to normal within two weeks of treatment. Laboratory parameters, especially the ECP, were similarly normalized. Churg-Strauss syndrome should be considered in the differential diagnosis of unexplained polyneuropathy. Determination of ECP may not only help in the diagnosis but does also facilitate monitoring of treatment and of further course of the disease.