Case: A 36-year-old female healthcare worker with no past medical history, accidentally injected her flexed right middle finger with live attenuated Mycobacterium bovis bacillus Calmette-Guérin (BCG). Swelling and erythema around the injured area appeared two days after the needlestick injury. She was referred to the hospital and presented approximately nine days after self-inoculation. Surgical debridement was immediately performed. After 38 days, colonies were observed on cultures of the removed tissue on Ogawa's medium. This isolate was identified as M. bovis BCG by polymerase chain reaction (PCR) based on RD1 gene deletion. She had a history of BCG vaccination and her skin lesion appeared immediately after the accidental injection of M. bovis BCG. Therefore, in the differential diagnosis, the possibility that the lesion was an allergic reaction to BCG was considered. The subsequent culture results came back positive for M. bovis BCG and acute tenosynovitis caused by M. bovis BCG was diagnosed. The skin lesion was treated with anti-mycobacterial drugs and resolved.
Discussion: The allergic reactions to BCG should be considered in the differential diagnosis of skin lesions following BCG vaccination. It is important to promptly submit a specimen for culture as delayed initiation of appropriate treatment can lead to a poor prognosis. In patients with accidental injection of M. bovis BCG, it is important to consider timely surgical excision and appropriate antimycobacterial therapy.
Keywords: Accidental injection; Mycobacterial infection; Mycobacterium bovis bacillus Calmette-Guérin (BCG); Mycobacterium tuberculosis; Tenosynovitis.
© 2023 The Authors.