Polymyositis associated with primary cytomegalovirus infection.

A case of polymyositis associated with primary cytomegalovirus infection in a 17-y-old girl is reported. The girl exhibited fever, sore throat, progressive myalgia and muscle weakness with elevated creatine kinase, atypical lymphocytosis and myopathic features in the electromyogram. Histopathologically, biopsied muscle met the criteria for polymyositis. Primary cytomegalovirus infection was proven by seroconversion of IgG as well as IgM antibodies. This is the first report of an association between cytomegalovirus infection and polymyositis.