LAUSR

A 60‐year‐old woman with a history of trigger finger presented with a 2‐week history of a swollen right middle finger. She had received local steroid injections twice for trigger finger 1 month before the visit. Unfortunately, the injection site became red, swollen and painful [Figure 1a]. No evidence of immunosuppression was proven by tests for human immunodeficiency virus, hepatitis B virus, hepatitis C virus and diabetes. She subsequently underwent local debridement. On incision, there was serosanguinous discharge and necrotic synovitis of the volar side of the right third metacarpal head region [Figure 1b]. Histopathological examination revealed numerous spore‐like microorganisms in the necrotic debris [Figure 2]. Numerous endospores with occasional floret‐like arrangement were identified on periodic acid‐Schiff and silver stains [Figure 3]. Tissue cultures were set up on blood agar plate and Sabouraud dextrose agar. The wet mount revealed round‐to‐oval spores of varying sizes (about 10–20 μ) with varying number of endospores inside.