Shihao Zheng, Jiaqi Li, Xiaodi Zou, Hui Lu, Tao Jiang
Corynebacterium minutissimum (C. minutissimum) is usually considered a skin commensal and is best known as the causative organism of erythrasma. Although invasive infections caused by this organism are rare, its clinical significance can be difficult to determine when it is isolated from wound specimens. Here, we present the case of a 14-year-old boy with progressive ulceration, swelling, malodor, and soft tissue destruction of the left lower leg. Intraoperative exploration revealed areas of nonviable fascia and adjacent soft tissue with purulent exudation, and a diagnosis of necrotizing soft tissue infection (NSTI) was made based on intraoperative findings. Surgical debridement was performed to remove visibly nonviable tissue, followed by temporary wound management using antibiotic-loaded bone cement. A deep purulent specimen obtained during surgery grew C. minutissimum, whereas anaerobic and fungal cultures showed no growth. After local infection control was achieved, the patient underwent repeat debridement and pedicled fascial flap reconstruction, with satisfactory wound healing and no evidence of recurrent infection during follow-up. Although the isolation of C. minutissimum was considered clinically relevant in this case, its role as the sole causative organism could not be confirmed because only one positive culture was available and additional microbiological evidence was lacking. This case illustrates the challenges in interpreting uncommon skin-associated organisms isolated from complex wounds and emphasizes that microbiological results should be assessed together with specimen characteristics, operative findings, clinical course, and treatment response. Early surgical debridement and staged reconstruction remain essential for achieving infection control and functional recovery in patients with NSTI.