Eosinophilic myopathic syndromes.

Eosinophilic infiltration into skeletal muscle, although rare, has been described in a diverse group of conditions. It most commonly occurs in parasitic infection as focal eosinophilic myositis but can be a feature of systemic hypereosinophilic conditions such as eosinophilia-myalgia syndrome and idiopathic hypereosinophilic syndrome. The majority of cases have no discernible etiological factor. Eosinophilic myopathies should be distinguished from the commoner idiopathic inflammatory myopathies such as polymyositis and dermatomyositis. This report describes the various conditions in which eosinophilic myopathy occurs and reviews the current state of knowledge of eosinophilic myopathy.