Atypical Mycobacteria have been widely known to cause opportunistic infections in patients with AIDS. Recently, cases have been reported of patients colonized with atypical Mycobacteria who are only partially responsive to antibacterial treatment. It is thought that perhaps these cases represent a clinically different subset of patients that not only have underlying infection, but hypersensitivity disease as well, which may be responsive to concomitant treatment with oral corticosteroids.