Necrobiosis lipoidica diabeticorum is an uncommon skin condition related to diabetes. It results in reddish brown areas of the skin, most commonly on the lower legs.
The cause of necrobiosis lipoidica diabeticorum (NLD) is unknown. It is thought to be linked to blood vessel inflammation related to autoimmune factors. This damages proteins in the skin (collagen).
People with type 1 diabetes are more likely to get NLD than those with type 2 diabetes. Women are more affected than men. Smoking increases the risk for NLD. Less than one half of one percent of those with diabetes suffer from this problem.
A skin lesion is an area of skin that is different from the skin around it. With NLD, lesions start as firm, smooth, red bumps (papules) on the shins and lower part of the legs. They usually appear in the same areas on opposite sides of the body. They are painless in the early stage.
As the papules become bigger, they flatten down. They develop a shiny yellow brown center with raised red to purplish edges. Veins are visible below the yellow part of the lesions. The lesions are irregularly round or oval with well-defined borders. They can spread and join together to give the appearance of a patch.
Lesions can also occur on the forearms. Rarely, they may occur on the stomach, face, scalp, palms, and soles of the feet.
Trauma may cause the lesions to develop ulcers. Nodules also may develop. The area may become very itchy and painful.
NLD is different from ulcers that can occur on the feet or ankles in people with diabetes.
Your health care provider can examine your skin to confirm the diagnosis.
If needed, your provider may do a punch biopsy to diagnose the disease. The biopsy removes a sample of tissue from the edge of the lesion.
Your provider may do a glucose tolerance test to see if you have diabetes.
NLD can be difficult to treat. Control of blood glucose does not improve symptoms.
Treatment may include:
In severe cases, the lesion may be removed by surgery, followed by moving (grafting) skin from other parts of body to the operated area.
During treatment, monitor your glucose level as instructed. Avoid injury to the area to prevent the lesions from turning into ulcers.
If you develop ulcers, follow steps on how to take care of the ulcers.
If you smoke, you will be advised to quit. Smoking can slow healing of the lesions.
NLD is a long-term disease. Lesions do not heal well and can recur. Ulcers are difficult to treat. The appearance of the skin may take a long time to become normal, even after treatment.
NLD can rarely result in skin cancer (squamous cell carcinoma).
Those with NLD are at increased risk for:
Call your provider if you have diabetes and notice non-healing lesions on your body, especially on the lower part of legs.
Reviewed By: Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.