Necrobiosis lipoidica (NL) is a rare inflammatory skin condition that can cause patches of skin that can sometimes develop into ulcers.

According to the American Diabetes Association, NL typically occurs in people who have diabetes.

In this article, learn more about NL, including the main symptoms, causes, and risk factors. The article also looks at the treatment options available and when a person should seek medical attention.

According to the Genetic and Rare Diseases Information Center, NL is a rare inflammatory skin condition that typically affects the lower legs.

Although anyone can develop NL, it typically affects those with type 1 diabetes.

NL usually appears as patches, or lesions, on the lower legs or shins. It can also appear elsewhere on the body — such as on the upper legs, hands, arms, torso, face, or scalp — though this is rare.

People with NL may notice one or more shiny, raised, flushed patches of skin on the lower legs. These may also be itchy or painful. The centers of the patches can become pale with visible blood vessels.

According to one 2020 article, these lesions tend to begin as small, firm papules that become bigger over time.

Ulceration can occur following minor trauma to the skin. Roughly a third of the lesions can become ulcerated.

Healthcare professionals do not know the cause of NL. However, some people may be more at risk of developing it than others.

NL can occur in both type 1 and 2 diabetes, affecting around 0.3% of those with diabetes.

People who smoke are also more at risk of developing skin ulcers, as smoking slows down the body’s ability to heal wounds.

It also appears to be up to five times more likely to affect females than males. However, according to one 2020 article, ulceration occurs in 58% of males and 15% of females.

According to a 2019 study, healthcare professionals associate the following conditions with an increased risk of developing NL:

People who have symptoms of NL should see a doctor as soon as possible. Although the condition itself is harmless, complications such as infection or scarring can sometimes occur.

A doctor will examine the site and ask about any underlying health conditions to help diagnose NL.

If they are in any doubt, the doctor may take a small sample (biopsy) of the affected tissue for testing. They will do this using local anesthetic.

A doctor may also ask about any other symptoms or arrange for additional tests to look for underlying health conditions, such as diabetes or a thyroid condition.

It is best to start treatment for NL at an early stage, to reduce the risk of ulcers developing and subsequent scarring.

However, if the condition is mild, simply monitoring it may be enough. According to a 2020 article, around 17% of lesions can resolve spontaneously.

NL is a chronic condition, which means that it can be lifelong. People may have permanent symptoms or symptoms that flare up from time to time.

To date, there is no particular successful treatment for NL. However, there are some options that may be effective.

A doctor may recommend one or a combination of the following treatments depending on the severity of the symptoms:

  • oral corticosteroids, such as prednisone
  • corticosteroid injections into the inflamed areas of skin
  • antimalarial drugs, such as hydroxychloroquine, to reduce inflammation
  • UV light treatment, to help control flare-ups
  • photodynamic therapy
  • laser treatment, to improve the appearance of blood vessels
  • immunomodulating drugs, such as cyclosporine, to help heal ulcers
  • medications to thin the blood, such as aspirin
  • surgical removal of the lesions and grafting to repair the skin

According to the British Association of Dermatologists (BAD), a doctor may also provide advice on what people with NL can do at home to control or improve the appearance of patches.

For example, they can try to avoid sustaining injury or trauma to the affected area by using padded dressings, shin guards, or support stockings. They can also try to stop smoking. This can help reduce the risk of ulcers forming and improve the body’s ability to heal.

If there is an underlying health condition, such as diabetes, working with a doctor to keep blood sugar levels under control may help. Although this may not improve NL, it may help reduce the risk of infection.

People who think they may have NL should always see a doctor. They may have an undiagnosed health condition that is causing the skin to flare up.

People with diagnosed NL should see a doctor if they notice a lump, persistent scab, or ulcer developing on the skin. The condition is not cancerous, but “there is a very small risk of skin cancer developing in longstanding lesions,” according to the BAD.

NL is an inflammatory skin condition. It often develops alongside diabetes. However, experts do not fully understand why certain health conditions are associated with it.

The symptoms include patches or lesions, usually on the shins, that sometimes develop into ulcers. The condition is not always painful, though some people may experience pain or itching in the affected areas.

There is no one treatment that works for everyone, and the condition is chronic. However, there are several treatment options that may help control the condition and improve the skin’s appearance.

People with suspected NL should see a doctor. The doctor can help them manage any existing underlying health conditions or identify previously undiagnosed health conditions.

People with diagnosed NL can take some measures at home to reduce the risk of developing ulcers and infection, such as avoiding injury and stopping smoking.