Diabetes-Related Foot Infections: Diagnosis and Treatment

Diabetes-related foot infections occur in approximately 40% of diabetes-related foot ulcers and cause significant morbidity. Clinicians should consider patient risk factors (e.g., presence of foot ulcers greater than 2 cm, uncontrolled diabetes mellitus, poor vascular perfusion, comorbid illness) when evaluating for a foot infection or osteomyelitis. Indicators of infection include erythema, induration, tenderness, warmth, and drainage. Superficial wound cultures should be avoided because of the high rate of contaminants. Deep cultures obtained through aseptic procedures (e.g., incision and drainage, debridement, bone culture) help guide treatment. Plain radiography is used for initial imaging if osteomyelitis is suspected; however, magnetic resonance imaging or computed tomography may help if radiography is inconclusive, the extent of infection is unknown, or if the infection orientation needs to be determined to help in surgical planning. Staphylococcus aureus and Streptococcus agalactiae are the most commonly isolated pathogens, although polymicrobial infections are common. Antibiotic therapy should cover commonly isolated organisms and reflect local resistance patterns, patient preference, and the severity of the foot infection. Mild and some moderate infections may be treated with oral antibiotics. Severe infections require intravenous antibiotics. Treatment duration is typically one to two weeks and is longer for slowly resolving infections or osteomyelitis. Severe or persistent infections may require surgery and specialized team-based wound care. Although widely recommended, there is little evidence on the effectiveness of primary prevention strategies. Systematic assessment, counseling, and comorbidity management are hallmarks of effective secondary prevention for diabetes-related foot infections.