Characteristics and pathogenesis of myositis in human immunodeficiency virus infection―Distinction from azidothymidine-induced myopathy

: Inflammatory muscle involvement during the course of human immunodeficiency virus (HIV) infection is described and guidelines are suggested for its differentiation from the myopathy associated with azidothymidine (AZT) therapy. Six patients infected with HIV presented with proximal muscle weakness, biochemical and electromyographic abnormalities consistent with myositis. One patient had a skin rash characteristic of dermatomyositis. Muscle biopsy findings demonstrated the presence of an inflammatory cell infiltrate and HIV-p24 antigen. All patients developed their clinical picture prior to AZT therapy and responded to steroids with or without coadministration of AZT.