Diabetic foot infection versus non-infected diabetic foot: contemporary diagnostic criteria, management algorithms, and clinical pitfalls: a focus on differentiating infectious and ischemic etiologies in diabetic foot ulcers

Diabetic foot ulcers (DFUs) represent a significant complication of diabetes mellitus, with infection (DFI) and critical limb ischemia (CLI) being key determinants of morbidity and amputation risk. Despite established guidelines from the infectious diseases society of America (IDSA) and the international working group on the diabetic foot (IWGDF), misdiagnosis between infected and non-infected (particularly ischemic) DFUs remains a frequent clinical challenge, leading to inappropriate antimicrobial therapy or delayed revascularization. This review examines the current diagnostic criteria for DFI, contrasts them with ischemic presentations, and highlights common errors in management, emphasizing evidence-based strategies to optimize outcomes. A narrative synthesis of IDSA/IWGDF guidelines, recent literature on DFU classification systems (e.g., SINBAD, WIfI), and clinical studies on biomarkers (e.g., procalcitonin, CRP) and imaging modalities (MRI, PET-CT) was conducted. Key discriminators between DFI and CLI include localized vs. diffuse erythema, systemic inflammatory response, and perfusion assessment (ABI, TcPO₂). Overreliance on superficial wound cultures and underutilization of bone biopsy in osteomyelitis are recurrent errors. Multidisciplinary teams (MDTs) integrating infectious disease, vascular surgery, and podiatry reduce misclassification rates. Distinguishing DFI from CLI requires systematic evaluation of clinical, laboratory, and vascular parameters. Enhanced clinician awareness of IDSA/IWGDF criteria and ischemic mimics may reduce diagnostic errors and improve limb salvage rates.