Opportunistic Infections in Patients with Temporal Arteritis Treated with Corticosteroids

emporal arteritis and polymyalgia rheumatica, different T clinical manifestations of the same systemic granulomatous vasculitis, predominantly affect older persons.' Huston and colleagues estimated the prevalence to be 1 in 750 persons older than 50 years of age.' Temporal arteritis often requires high and sometimes sustained corticosteroid therapy to prevent the development of sight threatening complications.'-' Often, corticosteroids alone are used for the entire length of the treatment course, which may exceed 1 year. This is in contrast to other collagen vascular diseases/vasculitides, in which other steroid-sparing immunosuppressive agents are used in combination to reduce the dose of corticosteroids.8 Corticosteroids exert their immunosuppressive effect principally on cell-mediated immunity.' This arm of the immune system is particularly important for defense against a variety of different intracellular pathogens. Thus, patients receiving corticosteroid therapy are at increased risk of infection caused by intracellular organisms. Although intracellular pathogens are frequently thought of in the differential diagnosis of pneumonia and sepsis syndrome in patients with hematological malignancies or transplants, these types of pathogens are rarely considered in the differential diagnosis of patients with temporal arteritis. We report the cases of three patients who received corticosteroids for temporal arteritis and who subsequently were infected with opportunistic pathogens. In all three, the opportunistic infection was not considered with the initial diagnosis.