Mycobacterium chelonae hand infection after steroid injection in a patient with rheumatoid arthritis receiving long-term linezolid therapy.

A 66-year-old multimorbid man with rheumatoid arthritis developed an infection after a steroid injection in the hand. Mycobacterium chelonae was cultured 1-month after presentation. In the mean time, his third finger had been amputated. Further treatment was based on preliminary susceptibility testing and the American Thoracic Society guidelines. No regression of the infection was observed before the addition of linezolid (600 mg×1/day) to a combination antimicrobial therapy also consisting of clarithromycin (500 mg×2/day) and moxifloxacin (400 mg×1/day), even though two methods of susceptibility testing, the E-test and broth microdilution, had shown susceptibility to other antimicrobial drugs. The healing was complete 12 months after presentation. There were no serious side effects observed with the use of linezolid in reduced dosage of 600 mg×1/day for a duration of 9 months.