Necrobiosis Lipoidica Diabeticorum

This is an answer to the Case – Yellow–brown Plaques with Ulcerations and Telangiectases

A 52-year-old man with diabetes reported a 3-month history of a pretibial rash during a routine visit. He had a 15-year history of type 2 diabetes mellitus treated with insulin and a 3-year history of congestive heart failure.

The lesions had begun to ulcerate and bleed but were not pruritic or painful. Physical examination showed yellow–brown plaques with ulcerations and telangiectases in the thinned epidermis.

A diagnosis of necrobiosis lipoidica diabeticorum — an inflammatory skin disorder characterized by irregularly shaped, callous lesions with reddish-brown pigmentation and central atrophy — was made on the basis of visual inspection.

In necrobiosis lipoidica diabeticorum, the shins, ankles, and feet are typically affected, but 15% of patients may have lesions elsewhere. The disorder is more common among women than men and is more common among persons with diabetes than those without.

Microscopical studies have shown that it is a disorder of collagen degeneration characterized by a granulomatous response, thickening of the walls of blood vessels, and fat deposition. The exact cause is unknown.

Necrobiosis lipoidica diabeticorum may be an antibody-mediated vasculitis with secondary collagen degeneration or the microangiopathy of diabetes (but it is not correlated with the extent of glucose control).

Treatment may include:

  • occlusive dressings
  • topical and subcutaneous corticosteroids
  • antiplatelet therapy

Flare-ups are frequent. No treatment is completely effective. The patient was referred to a dermatologist for continuing care, but he died suddenly at home.