A nonimmunocompromised 77-year-old man was bitten in the hand by his dog; redness, swelling, and exudate developed. Despite debridement and medications administered at another hospital, his symptoms did not improve. He was referred to us after 3 months. Debridement and negative-pressure wound therapy was performed. Cultures were positive for multiple bacterial organisms, including Mycobacterium chelonae. Polymicrobial extensor tenosynovitis including M. chelonae was diagnosed. Clarithromycin was given for 7 months based on drug sensitivity. His symptoms did not recur.
Mycobacterium chelonae infections after dog bites are rare; however, mycobacterial culture tests are important, especially if tissue shows granulomatous inflammation.