(From Pei-Shan Yen, Kuo-Hsien Wang, Wei-Yu Chen, Ya-Wen Yang, Wen-Tsao Ho, 2011. The many faces of necrobiosis lipoidica: a report of three cases with histologic variations. Dermatologica Sinica 29 (2), 67–71.)
Necrobiosis lipoidica (NL) is a chronic cutaneous granulomatous condition with degenerative connective tissue changes. The pathophysiology remains unknown but both granulomatous and angiopathic mechanisms have been proposed. It is seen in 1 in 300 diabetics but may be unassociated with glucose intolerance. NL initially appears as an atrophic plaque found over pretibial sites. Ulceration may occur after trauma, with ensuing pain. NL may rarely be complicated by squamous cell carcinoma.
Smoking cessation and avoiding trauma to the affected shins are key factors to avoid transformation from an unsightly plaque into a painful, recalcitrant ulcer. The progression of new lesions may be halted by intralesional or occluded potent topical corticosteroids applied to the margins of the lesions. Once atrophy has developed there is little that will reverse this, although topical retinoids may be tried. Telangiectasia is often marked and has been treated with pulsed dye laser. Extensive lesions may justify trials of nicotinamide or prednisolone. Antiplatelet therapy in the form of aspirin, dipyridamole, or ticlopidine has its enthusiasts, though responses are inconclusive. Topical psoralen and UVA (PUVA) has received recent interest and may arrest progression and improve the appearance. A variety of systemic anti-inflammatory and immunosuppressive agents have received recent attention, including mycophenolate mofetil, fumaric acid esters, cyclosporine, antimalarials, thalidomide, and pentoxifylline. Infliximab and etanercept have also been proposed.
The chronically ulcerated lesion is a challenge; antibiotics deal with secondary infection, appropriate dressings may be required, and growth factors such as becaplermin and granulocyte–macrophage colony-stimulating factor (GM-CSF) may accelerate healing. As diabetics may have coexisting large vessel atherosclerosis that may contribute to ulceration, non-invasive arterial studies or angiography need to be considered if clinically indicated. Venous hypertension may also contribute to the localization and ulceration of necrobiosis. Excision and grafting may transform the patient’s quality of life and improve cosmesis.
Necrobiosis lipoidica diabeticorum: association with background retinopathy, smoking, and proteinuria. A case controlled study.
The patient should stop smoking and control diabetes mellitus with vigilance. Fifteen diabetic patients with NL were each matched with five control subjects with diabetes mellitus. Background retinopathy, proteinuria, and smoking were all more common with NL. No differences were noted between those with NL and controls in the prevalence of vascular disease and neuropathy. Glycosylated hemoglobin concentrations were higher in patients with NL.
Three of five cases of NL underwent complete resolution and one had partial improvement with 5 mg/mL triamcinolone injection to the edges of lesions. No serious complications of this type of treatment were observed.