[Diabetes mellitus and skin diseases]

Diabetes mellitus is defined as an hereditary chronic metabolic disease due to an absolute or relative shortage of insulin. There are various types to be differentiated, among others, (I) the insulin-dependent and mostly juvenile type, and (II) the insulin-independent type, which mainly appears in later life. We discuss three main groups of cutaneous diseases. Infections of the skin and underlying tissue predominantly occur along with an acutely disturbed metabolic situation. The late diabetic syndrome includes macroangiopathy (arteriosclerosis) and microangiopathy (rubeosis, necrobiotic granulomas, diabetic skin spots, epidermolysis bullosa diabetica, gangrene). Owing to failure of sensible, motor, or autonomous fibers, diabetic neuropathy may lead to various symptoms - in the extreme case, to neuropathic malum perforans. The diabetic foot represents a collection of various diabetic complications in both early and late stages.