Necrobiosis Lipoidica Diabeticorum

Necrobiosis lipoidica diabeticorum (NLD) is an idiopathic chronic granulomatous disease characterized by collagen degeneration, granuloma formation, fat deposition, and vascular endothelial wall thickening.
NLD is seen more frequently in type 1 than in type 2 diabetes and may occur before the onset of clinical diabetes.
A minority of patients have no clinical evidence or family history of diabetes; in these patients, the term necrobiosis lipoidica is used.
Currently, the term necrobiosis lipoidica is used to encompass all patients with the same clinical lesions regardless of whether diabetes is present or not, since these lesions have also been described in patients with sarcoidosis, inflammatory bowel disease, and in otherwise healthy patients.

Clinical Manifestations ⬆ ⬇

NLD is more commonly seen in women than in men.
Lesions appear most commonly on the pretibial areas; rarely they may arise on other sites such as the scalp, face, groin, and upper extremities.
Lesions typically arise as one to three asymptomatic papules and nodules with erythematous borders that coalesce into atrophic plaques.
The plaques are characteristically translucent yellow-red to brown in color as epidermal atrophy and telangiectasias become evident (Fig. 34.1). As lesions progress, the center becomes depressed and yellowish in color (Fig. 34.2).
Ulceration resulting in pain may occur.
The condition is typically chronic with variable progression and scarring.

Diagnosis ⬆

Differential Diagnosis

The lesions of NLD can be similar to those of morphea (see later discussion) and other localized sclerosing lesions.

Management

High-potency topical steroids or intralesional steroid injections are used to lessen the inflammation of early active lesions and the active borders of enlarging lesions, but these have little beneficial effect on atrophic plaques. In fact, steroid use may cause further atrophy.
Because localized trauma can cause NLD to ulcerate, protection of the legs with support stockings is helpful.
Antiplatelet aggregation therapy with aspirin and dipyridamole has produced varied results.
Pentoxifylline (Trental) may be prescribed because of its inhibition of platelet aggregation, and its fibrinolytic activity.
Topical application of bovine collagen is believed to improve granulation tissue by supporting fibroblast activity and promote wound debridement by increasing the number of macrophages and neutrophils at the wound site.
Ticlopidine, nicotinamide, clofazimine, and perilesional heparin injections have been used in uncontrolled studies and appeared to benefit some patients with NLD.
Immunosuppressants, intralesional infliximab, colchicine, photodynamic therapy, and topical calcineurin inhibitors (Protopic ointment [tacrolimus] 0.1% or Elidel cream 1% [pimecrolimus]) have been used with reported efficacy.