Early Diagnosis of Streptococcal Toxic Shock Syndrome With Abdominal Computed Tomography: A Case Report

Streptococcal toxic shock syndrome (STSS) is a rapidly progressive and highly lethal infection caused by group A streptococcus, in which early diagnosis remains challenging due to nonspecific initial symptoms. We report a case of a 37-year-old woman who developed severe abdominal pain 24 hours after outpatient cervical polypectomy, with progression to septic shock at 48 hours post-procedure, presenting with hypotension, diffuse erythema, leukopenia, acute kidney injury, and elevated inflammatory markers. Contrast-enhanced abdominal computed tomography (CT) demonstrated pelvic-predominant peritoneal thickening, uniform small-bowel wall thickening with serosal thickening, and mesenteric vascular engorgement, findings suggestive of toxin-mediated peritonitis rather than primary enteritis. Based on clinical presentation and CT findings, invasive group A streptococcal infection with STSS was strongly suspected, prompting immediate treatment with meropenem plus clindamycin and hemodynamic support before obtaining the blood culture result. The next day, blood cultures confirmed Streptococcus pyogenes, establishing the diagnosis of STSS. The patient achieved hemodynamic stability within 24 hours of appropriate antibiotic therapy, ultimately recovering without major disability, and was discharged on Day 44. This case demonstrates that contrast-enhanced CT can provide crucial diagnostic information for early STSS recognition, particularly the characteristic pattern of pelvic-centered peritonitis with small bowel involvement, and when STSS is strongly suspected based on clinical history and CT findings following minor gynecologic procedures, clinicians should consider initiating β-lactam plus clindamycin therapy without waiting for culture confirmation to optimize patient outcomes.