Necrobiosis lipoidica diabeticorum, also called NLD, is a rare disorder that produces large, usually painless skin lesions on the lower legs. As its name suggests, necrobiosis lipoidica diabeticorum is most commonly seen in patients who have diabetes. Over the course of several months or years, small red or brown patches of skin develop into yellow, shiny ulcers on the shins. The ulcers themselves do not typically cause health problems, but people often choose to undergo treatment to improve their appearance and lessen the risk of infection.
Doctors do not have a clear understanding of why or even how necrobiosis lipoidica diabeticorum develops. Since diabetes is an underlying condition in almost all cases, it is thought that blood vessel diseases common in diabetic patients are responsible for leg ulcers. Abnormally high blood glucose levels cause the tiny blood vessels in the legs to thicken, swell, and eventually rupture. Since blood vessels in the legs are very close to the surface of the skin, inflammation and bleeding can cause ulceration.
In most cases, necrobiosis lipoidica diabeticorum develops very slowly. A person first notices a collection of red, slightly raised bumps that gradually turn brown and appear to spread. As an ulcer grows, it turns yellow in the center and takes on a shiny, wax-like appearance. It is uncommon for lesions to itch or cause pain, but a broken area of skin may become infected and lead to additional symptoms. Ulcers are restricted to the shins in nearly all cases, though the condition can rarely appear on the hands, forearms, or face as well.
A doctor can diagnose necrobiosis lipoidica diabeticorum by carefully examining skin ulcers and asking about a patient's medical history. A small sample of skin tissue may be collected for histological analysis. Medical lab scientists can inspect tissue to determine if the appearance of blood and fat cells is consistent with the pathology of necrobiosis lipoidica diabeticorum. If a patient has not yet been diagnosed with diabetes, blood tests are typically performed to confirm or rule out the condition.
Treatment measures depend on the size and severity of ulcers. In most cases, doctors focus on limiting the risk of infections by suggesting that patients protect their legs and use topical antibiotics on open wounds. Topical and injected corticosteroids are occasionally used to reduce inflammation in developing lesions.
Surgery is not often recommended, but a person who is concerned about the aesthetic appearance of his or her legs can elect to have a procedure done. A plastic surgeon can excise lesions and graft skin tissue from elsewhere on the body onto the shins. It is possible, however, for necrobiosis lipoidica diabeticorum to return after surgery.