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A woman with a history of diabetes, and plaques on both shins

Courtesy Dr. Donna Bilu Martin
A 28-year-old White female with a history of diabetes mellitus presents with asymptomatic plaques on her bilateral shins present for over 5 years. She had previously been treated with intralesional and topical steroids and laser treatment.

What's your diagnosis?

Diabetic dermopathy

Granuloma annulare

Necrobiosis lipoidica

Sarcoidosis

Necrobiosis lipoidica, or Necrobiosis lipoidica diabeticorum (NLD), is an uncommon dermatologic condition that presents as plaques on the skin. Women are often more affected than men. Patients often present in their 30s and 40s. The cause of NLD is unknown. Twenty percent of patients with NLD will have glucose intolerance or a family history of diabetes.1 The percentage of patients with NLD who have diabetes varies in reports from 11% to 65%.2 NLD may progress despite the diabetes treatment. Only 0.03% of patient with diabetes will have NLD.3

Dr. Donna Bilu Martin

Lesions most commonly occur on the extremities, with shins being affected in most cases. They vary from asymptomatic to painful. Typically, lesions begin as small, firm erythematous papules that evolve into shiny, well-defined plaques. In older plaques, the center will often appear yellow, depressed, and atrophic, with telangiectasias. The periphery appears pink to violaceous to brown. Ulceration may be present, particularly after trauma, and there may be decreased sensation in the plaques. NLD is clinically distinct from diabetic dermopathy, which appear as brown macules, often in older patients with diabetes.

Ideally, biopsy should be taken at the edge of a lesion. Histologically, the epidermis appears normal or atrophic. A diffuse palisaded and interstitial granulomatous dermatitis consisting of histiocytes, multinucleated giant cells, lymphocytes, and plasma cells is seen in the dermis. Granulomas are often oriented parallel to the epidermis. There is no mucin at the center of the granulomas (as seen in granuloma annulare). Inflammation may extend into the subcutaneous fat. Asteroid bodies (as seen in sarcoid) are absent.

Unfortunately, treatment of NLD is often unsuccessful. Treatment includes potent topical corticosteroids for early lesions and intralesional triamcinolone to the leading edge of lesions. Care should be taken to avoid injecting centrally where atrophy and ulceration may result. Systemic steroids may be helpful in some cases, but can elevate glucose levels. Other reported medical treatments include pentoxifylline, cyclosporine, and niacinamide. Some lesions may spontaneously resolve. Ulcerations may require surgical excision with grafting.

This case and photo are provided by Dr. Bilu Martin, who is a board-certified dermatologist in private practice at Premier Dermatology, MD, in Aventura, Fla. More diagnostic cases are available at mdedge.com/dermatology. To submit a case for possible publication, send an email to [email protected].

References

1. James WD et al. Andrews’ Diseases of the Skin: Clinical Dermatology. Philadelphia: Saunders Elsevier, 2006.

2. Hashemi D et al. JAMA Dermatol. 2019 Apr 1;155(4):455-9.

3. Bolognia JL et al. Dermatology. St. Louis, Mo.: Mosby Elsevier, 2008.

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