Itchy Skin and Diabetes. Itchy skin can be a sign of diabetes, particularly if other diabetes symptoms are also present. High blood sugar levels over a prolong period of time is one cause of itchy skin. In some cases, itchy skin may be caused by complications of diabetes such as nerve damage or kidney disease. Itching of the feet, legs or ankles is a common complaint in people with diabetes that may occur as a result of a period of too high sugar levels. Itching can range from being annoying to severe. Itching can be relieved through treatment, and may be eliminated if the underlying cause is treated. Causes of itchy skin