Eosinophilia and musculoskeletal disease

Eosinophilia is occasionally a feature of rheumatic disease. The differenti al diagnosis of eosinophilia includes parasitic infection, systemic vasculi tides, eosinophilic arthritis. and myopathies, together with the idiopathic hypereosinophilic syndrome and malignancy. Careful evaluation of the patie nt should enable an accurate diagnosis to be made. Parasitic infection is t he commonest cause of eosinophilia worldwide and can cause systemic disease , as illustrated by the report of Sarcocystis myositis in a group of milita ry personnel in Malaysia, A persistent arthropathy associated with eosinoph ilia, but not with parasitic infection, has been reported from the far East . Drugs may also cause eosinophilia, and there has recently been much discu ssion of the relation between Churg-Strauss syndrome and the leukotriene an tagonist zafirlukast. The present view is that reduction of steroid dose al lows unmasking of previously undiagnosed Churg-Strauss syndrome. The idiopa thic hypereosinophilic syndrome may represent a lymphoproliferative process ; evidence for this comes from the demonstration that many patients have a clonally expanded population of aberrant T cells. Curr Opin Rheumatol 2001, 13:57-61 (C) 2001 Lippincott Williams & Wilkins, Inc.