Pyothorax caused by Nocardia otitidiscaviarum in a patient with rheumatoid vasculitis.

We report a case of pyothorax caused by Nocardia (N.) otitidiscaviarum infection in a 69-year-old man with rheumatoid vasculitis, who was regularly treated with prednisolone in our hospital. Initially, the patient responded poorly to intravenous imipenem/cilastatin (IPM/CS), minocyclin (MINO), and oral trimethoprim-sulfamethoxazole (TMP-SMX), but later improved after treatment with levofloxacin (LVFX) and gentamicin sulfate (GM) according to in vitro susceptibility tests. To our knowledge, this is the first description of pyothorax caused by N. otitidiscaviarum infection. It is a rare disease, but recognition of the disease in immunocompromised patients and the prompt initiation of appropriate treatments based on isolation of the pathogen and susceptibility testing can lead to a successful outcome.