Necrobiosis lipoidica diabeticorum (NLD) is a rare skin disease marked by discolored areas that are most often found on the lower legs. It usually affects people who have diabetes or a family history of diabetes. The cause is unclear, though it may be associated with impaired circulation, hyperglycemia, diabetic neuropathy or other complications of diabetes.

NLD may be considered cosmetically unattractive and can be itchy and painful. It is not usually a serious condition, and in some cases the lesions heal without treatment. NLD that causes skin ulcers is a concern for patients with diabetes because diabetes impairs healing, and the lesions can become infected and spread to other tissues.

The appearance of NLD varies, which sometimes complicates distinguishing NLD from other skin conditions, such as diabetic dermopathy. Often it begins as small reddish bumps that enlarge to waxy yellow lesions with a raised red or brown border. It usually appears on the shins but can occur on other parts of the body. Because the lesions described as NLD can vary, a tissue sample (biopsy) may be required for a correct diagnosis.

This condition may be chronic, though many cases do not require treatment. When skin ulcers are present, treatment can help prevent infection. A number of therapies including corticosteroids are available for NLD, but the treatments tend to have mixed success. Prevention may include control of diabetic risk factors.