Infections in the diabetic foot

Infection of the diabetic foot is usually a complication of neuropathic or neuroischemic ulcers and is a common cause of amputation in patients with diabetes. Patients with severe loss of sensation as a result of neuropathy do not feel pain and the diagnosis of the infected diabetic foot is delayed with devastating consequences for the foot or even for life. Mild infections may rapidly evolve into more severe infections within hours in patients with critical limb ischemia. Diagnosis of the infection is clinical. Paraclinical evaluation may be useful if deeper tissues are affected. There is a relationship between the severity of the infection and the kind as well as the number of the pathogens isolated from the infected wounds. In mild infections or in infections of moderate severity, Gram-positive bacteria are common responsible pathogens, among which staphylococci and streptococci species predominate. In more severe infections, additional pathogens, including Gram-positive, Gram-negative and anaerobic organisms, are often isolated. Culture of the base of the ulcer after debridement is necessary before initiation of treatment with antimicrobial agents. In ulcers that are not infected, cultures are not indicated; most importantly in such ulcers treatment with antimicrobials should not be initiated, as such treatments result in the development and predominance of resistant strains, which may be more virulent. Clinical examination, imaging studies and measurement of ESR and serum C-reactive protein as well as bone culture and biopsy are used for the diagnosis of osteomyelitis. Restoration of blood supply to the periphery is of crucial importance to the outcome of the infected foot ulcers. Adjuvant treatments include hyperbaric oxygen and colony-stimulating growth factor. The use of dressings with antimicrobial properties is recommended for the prevention of infections in ulcers with profuse exudate.