A previously healthy 37-year-old male developed rapidly progressive necrotizing fasciitis of the scrotum, perineum, and right lower extremity following minor bicycle-related abrasions, with Group A Streptococcus identified as the causative pathogen, according to a case report.
Researchers described the infection as one of the first reported cases in China of extensive necrotizing fasciitis secondary to minor trauma.
Clinical Presentation and Diagnostic Course
The researchers detailed that the symptoms began on March 20, 2022, as scrotal discomfort following a bicycle ride that resulted in superficial abrasions. The episode was preceded by alcohol consumption and prolonged lateral recumbency. Within 1 day, the patient developed bilateral scrotal erythema, purple discoloration, severe tenderness, and marked swelling, with pain extending to the right medial thigh.
Prior to admission, the patient was initially misdiagnosed with testicular torsion at a local hospital. After admission, he was again misdiagnosed—first with scrotal edema and then with drug-induced dermatitis following dermatologic consultation.
Laboratory findings on admission showed leukocytosis (12.4 × 10⁹/L) with neutrophils at 91%, elevated C-reactive protein levels (283 mg/L), and elevated procalcitonin (59 ng/mL). Hyponatremia (135 mmol/L) and acute kidney injury (creatinine 199 µmol/L) were also present. The findings corresponded to a Laboratory Risk Indicator for Necrotizing Fasciitis score of 8, placing the patient in a high-risk category.
Computed tomography demonstrated extensive subcutaneous edema and soft tissue thickening extending from the right hip to the pelvic floor and medial right thigh. Despite these findings, initial treatment with amikacin, dexamethasone, and parecoxib sodium followed by methylprednisolone and topical therapy didn't control disease progression. The researchers noted that corticosteroids and analgesics may have masked disease severity and potentially facilitated the spread of the infection.
Pathogen Identification and Clinical Deterioration
Wound smear findings prompted consultation with critical care physicians, and empirical antimicrobial therapy with linezolid and meropenem was initiated. Despite treatment, the infection progressed to involve the perianal region and right lower limb, with rapid deterioration to septic shock, heart failure, and acute renal failure within 72 hours of admission.
Microbiological testing confirmed Streptococcus pyogenes using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Susceptibility testing demonstrated sensitivity to penicillin and resistance to clindamycin.
The researchers noted that although international guidelines often recommend clindamycin for toxin suppression in Group A Streptococcus infections, resistance rates in China have been reported to be high, ranging from approximately 89% to 100%, supporting the initial use of linezolid in this case.
Treatment and Outcomes
After stabilization, emergency decompressive fasciotomy was performed. Surgical findings included necrotic adipose tissue with gray-white discoloration, abundant exudate, and vascular thrombosis, findings consistent with necrotizing fasciitis and confirming the diagnosis intraoperatively. A vacuum-assisted closure system was applied.
Antimicrobial therapy was adjusted to high-dose intravenous penicillin G with meropenem. Continuous renal replacement therapy was initiated, and intravenous immunoglobulin was administered for 3 days.
Within 2 days following surgery, inflammatory markers declined substantially. The patient also developed fluid-filled bullae on the right thigh surrounding the surgical wound, reflecting dermal-fascial separation associated with the infection. A second debridement was performed on day 11 of hospitalization. By day 21, the patient was transferred for skin grafting, and at 6-month follow-up, the wound had healed completely, with no residual organ dysfunction or recurrence.
Proposed Mechanism and Limitations
The researchers proposed a multifactorial mechanism in which alcohol consumption may have impaired the skin barrier, prolonged recumbency reduced local microcirculation, and cycling-related microtrauma created a portal of entry for infection. Although no throat culture was obtained, they suggested that transient bacteremia from an asymptomatic carrier state may have contributed.
As a single case report, the findings aren't generalizable.
Conclusion
According to lead report author Xiaohua Li, of the Department of Clinical Laboratory at Ordos Central Hospital in Inner Mongolia, China, and colleagues, the case showed that necrotizing fasciitis can develop following minor trauma even in patients without traditional risk factors. Early recognition using laboratory scoring systems and imaging, along with rapid multidisciplinary coordination, remains essential for favorable outcomes.
The researchers reported no competing interests and no external funding.
Source: BMC Infectious Diseases