This condition involves the degeneration of the collagen with a granulomatous response, thickening of the blood vessel walls, and fat deposition. It affects the shin of insulin-dependent diabetics, although it may occur in non-diabetic subjects as well. The cause of this condition is unknown.
Necrobiosis lipoidica is three to five times more common in females than in males. It can occur in both type 1 and type 2 diabetes, and patients with diabetes are more likely to be younger or male than those without diabetes. Other associations include obesity, hypertension, dyslipidemia, and thyroid disease.
- Occurs on both shins and are rarely found in other areas of the body
- The plaques may be asymptomatic or tender and may persist for years
- Plaques appear round, oval, or an irregular shape
- The center of the patch becomes shiny, pale, thinned, with prominent blood vessels (telangiectasia)
- An injury to the patch can cause it to ulcerate which could be very painful or painless
- Ulcers are at risk of secondary bacterial infection and delayed healing
- Ulcers also leave a dark scar
A skin biopsy may be performed to confirm the diagnosis of necrobiosis lipoidica. Histopathology would show a granulomatous inflammatory reaction around destroyed collagen.
Not all cases of necrobiosis lipoidica require treatment, but those that are ulcerating may require aggressive treatment. The following may be prescribed by the doctor: Topical steroids, usually under a plastic occlusive dressing
- Intralesional steroid injections or steroid tablets
- Aspirin and dipyridamole combination
- Oxypentifylline tablets
- Oral ciclosporin
- Biologic agents
- Photochemotherapy (PUVA)
- Photodynamic therapy
- Fumaric acid esters