[Pulmonary nocardiosis complicated with multiple brain abscess].

A 52-year-old woman was taking 10 mg of prednisolone on alternate days for the treatment of autoimmune hemolytic anemia. She was informed of an abnormality on a chest X-ray film about 3 months previously and was admitted to our hospital with sudden onset of chest pain and fever. On the following day, she underwent transthoracic needle biopsy and the lung lesion was diagnosed as pulmonary nocardiosis. She showed improvement of fever and the lung lesion with administration of an antibacterial agent, but suddenly developed vomiting and headache. Brain MRI revealed multiple brain abscesses at more than 20 sites. A subsequent change of the antibacterial agent achieved control of the lung lesion and brain lesions. This case shows that prednisolone can cause nocardiosis as an opportunistic infection even at a low dose and that antibacterial agents act differently on the lung and brain lesions caused by this organism.