Compromise of the blood supply from microvascular disease, often in association with lack of sensation because of neuropathy, predisposes persons with diabetes mellitus to foot infections. These infections span the spectrum from simple, superficial cellulitis to chronic osteomyelitis.
Diabetic foot infections typically take one of the following forms:
Deep-skin and soft-tissue infections
Tender, erythematous, nonraised skin lesions are present, sometimes with lymphangitis
Lymphangitis suggests group A streptococcal infection
Bullae are typical of Staphylococcus aureus infection, but occasionally occur with group A streptococci