[Subcutaneous abscess due to Nocardia farcinica].

An 64-year-old-woman with hypersensitivity pneumonia treated with combined of prednisolone and sulfamethoxazole and trimethoprim had a history of infectious pneumonia due to an unknown pathogen. About two weeks before she was first seen, she noticed right back swelling increasing rapidly in size and pain. Incision of the skin lesion produced a massive amount of pus and a pus smear showed acid-fast gram-positive branching filaments confirming diagnosis of nocardiosis. Symptoms decreased following open drainage and intravenous ceftriaxone and amikacin administration, but the woman died of urinary tract infection three months after diagnosis. Organisms isolated from pus were identified as Nocardia farcinica, thought to have infiltrated secondary from a pulmonary lesion to subcutaneous abcesses.