The Role of Infrared Thermography in the Diagnosis and Monitoring of Diabetic Foot Infection: A Systematic Review

Background: Diabetic foot infection (DFI) is one of the most frequent diabetes-related complications requiring hospitalisation and is a major contributor to lower-extremity amputation. Infrared thermography has emerged as a non-invasive diagnostic tool capable of detecting temperature changes associated with inflammatory and infectious processes. This systematic review aimed to evaluate the role of thermography in the diagnosis and monitoring of diabetic foot infection. Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was followed. Risk of bias and methodological quality were assessed using design-specific validated tools, including QUADAS-2 for diagnostic and detection studies and Joanna Briggs Institute critical appraisal checklists for cohort and case-series studies. Original studies evaluating the use of thermography in patients with diabetic foot infection were included. Two authors independently performed study selection, data extraction, and methodological assessment. Results: Six studies met the inclusion criteria, comprising a total of 552 participants with type 1 or type 2 diabetes mellitus. Four observational studies and two pilot studies were included. Increased local skin temperature was consistently associated with acute diabetic foot complications and infection. Several studies identified a temperature difference of approximately 2.2 °C between contralateral foot regions as a clinically relevant threshold for detecting diabetic foot complications. However, no significant relationship was found between plantar thermal asymmetry and the severity or progression of infected diabetic foot ulcers. All included studies presented a level of evidence of 4 and a grade of recommendation of C. Conclusions: Infrared thermography appears to be a promising adjunctive tool for the early detection of diabetic foot infection. However, current evidence does not support its routine use for monitoring infection severity, treatment response, or prognosis, and further prospective studies are required before these applications can be recommended.