Churg-Strauss syndrome presenting as myositis following unaccustomed exercise

A 68-year-old woman with a 4 year history of bronchial asthma developed marked myalgia in the extremities following exercise to which she was unaccustomed. Examination on admission, 11 days after onset, revealed myalgia, muscular weakness and cutaneous hemorrhagic bullae. Blood tests revealed eosinophilia (9160/mm(3)) and elevation of creatinine kinase and C-reactive protein. Muscle biopsy in the quadriceps femoris showed small vessel vasculitis and eosinophilic infiltration. Skin biopsy revealed leukocytoclastic vasculitis with neutrophilic and eosinophilic infiltration and fibrinoid necrosis. We diagnosed her as having Churg-Strauss syndrome (CSS). Corticosteroid treatment relieved her symptoms and resulted in normalization of the laboratory test results. Myositis is rare as an initial manifestation of CSS. The previous studies on immunological changes after eccentric exercise suggest that unaccustomed exercise could induce an increase in the serum level of interleukin-6 and trigger the onset of CSS.