Case Report: Necrotizing myositis secondary to a pararectal fistula: diagnostic challenges and multidisciplinary management.

BACKGROUND

Necrotizing soft tissue infections (NSTIs) are rare but life-threatening conditions requiring early diagnosis and aggressive multidisciplinary management. Necrotizing myositis (NM) is an uncommon and particularly severe manifestation, often associated with diagnostic delay and poor outcomes.

CASE PRESENTATION: We report the case of a 57-year-old man presenting with mild pelvic pain radiating to the posterior thigh. Contrast-enhanced computed tomography revealed a presacral abscess with an extrasphincteric fistulous tract extending into the posterior thigh musculature. Surgical exploration confirmed necrotizing fasciitis with myonecrosis caused by Group A Streptococcus. The patient underwent repeated surgical debridement, broad-spectrum antimicrobial therapy, and adjunctive hyperbaric oxygen therapy, resulting in progressive clinical improvement and complete recovery at six-month follow-up.

CONCLUSION

This case highlights the importance of early imaging, prompt source control, and multidisciplinary management in atypical NSTIs, while illustrating the potential adjunctive role of HBO2 in selected patients.