This report describes the coexistence of three patients with rheumatic diseases (systemic lupus erythematosus, rheumatoid arthritis, and dermatomyositis) and infections because of Histoplasma capsulatum. Connective tissue diseases and histoplasmosis share several clinical findings. Therefore, histoplasmosis could be misdiagnosed as connective tissue disease or a flare of these diseases. Such cases highlight the importance of awareness of histoplasmosis in immunocompromised patients, particularly in those originating from endemic areas.