Limb amputation in patients with pyoderma gangrenosum: a multi-institutional case series.

INTRODUCTION: Pyoderma gangrenosum (PG) can represent a diagnostic challenge, leading to missed or delayed diagnosis. With prolonged immunosuppressive therapy, the risk of infections is elevated, predisposing patients to receive anti-infective treatments and, in serious cases, amputations. Limb amputations have been reported as complication of PG misdiagnosis but can also occur as a complication of long-standing PG ulcers. METHODS: We aimed to describe the clinical characteristics of patients with PG leading to limb amputation through a multicenter retrospective case series between 2010 and 2020 including patients with PG who underwent limb amputation. We report a descriptive analysis of these patients' clinical course and outcome. RESULTS: Ten patients with PG who underwent at least one limb amputation were identified. Six were male (60%). Mean age was 65 years. All patients had ulcerative PG on the lower extremities, with a mean PG ulcer duration of 30.6 months. Six patients had PG-related comorbidities such as ulcerative colitis, myelodysplasia, and inflammatory arthritis. Other significant comorbidities included diabetes mellitus (DM) (five patients), coronary artery disease (five patients), and chronic kidney disease (two patients). The majority of patients (8/10) were correctly diagnosed with PG prior to amputation, whereas two patients were misdiagnosed with necrotizing soft tissue infections (NSTIs). All patients received intravenous antibiotics without substantial improvement. Eight patients developed sepsis and shock-like symptoms and the diagnosis of NSTIs was considered. Below-knee amputation was performed in six patients and above-knee amputation in four. Four patients had amputation performed twice because of recurrent NSTIs. Conclusion This multicenter case series sheds light on practice gaps for physician assessing patients with PG, in that limb amputation may result from PG misdiagnosis or complications thereof. Elderly patients (above 65 years) with coexisting lower extremity PG, DM, and/or chronic cardiac or renal disease should be managed with particular care toward preventing infection/NSTIs to prevent further complications such as limb amputations.