A 50-year-old Caucasian female with a history of hypertension, coronary artery disease, and insulin-dependent diabetes mellitus presents to the emergency department with a complaint of painful sores on the top of her left foot. She notes that ulcerations have formed over the past two weeks and reports a history of multiple recurrent usually non-tender skin lesions to her lower extremities, forearms, and hands over the past twenty years. She is homeless and medically non-compliant secondary to financial issues.
Skin: Multiple yellow-brown and violaceous plaques on the pretibial lower extremities and feet, some exhibiting ulceration with central necrosis and surrounding erythema. Raised reddish-brown well-demarcated plaques with waxy centers were also noted on the dorsal forearms and hands.
Necrobiosis Lipoidica – This patient had a previous skin biopsy with histopathologic changes demonstrating a granulomatous dermatitis involving the dermis and subcutaneous tissues with necrobiosis of collagen and inflammatory infiltrates of lymphocytes and plasma cells consistent with a diagnosis of necrobiosis lipoidica.
Necrobiosis lipoidica is a rare, chronic, idiopathic, granulomatous disease of collagen degeneration classically associated with type 1 diabetes (with a prevalence of 0.3 to 1.2%). It may present as the first clinical finding of or a precursor to diabetes, although its course is unaffected by glycemic control and it is unrelated to other diabetic complications including renal, ocular, and vascular problems. It has been associated with thyroid disease, inflammatory bowel disease, rheumatoid arthritis, and sarcoidosis. It may be equally common in patients without diabetes, hence was renamed without the term “diabeticorum”.
Necrobiosis lipoidica typically is asymptomatic and presents in females (average onset at age of 30) as small, well-demarcated papules that expand into waxy-centered plaques with indurated borders that may resolve spontaneously (up to 17%) or may be complicated by ulceration, infection, and occasionally transformation to squamous cell carcinoma. The differential diagnosis includes other granulomatous and inflammatory diseases such as granuloma annulare, sarcoidosis, rheumatoid arthritis, and necrobiotic xanthogranuloma. The diagnosis is suggested by clinical presentation and is proven by biopsy.
Complications of necrobiosis lipoidica include long-term scarring, ulceration (more common in males), infection, and when lesions are chronic they may rarely transform into squamous cell carcinoma. There is no cure for necrobiosis lipoidica, and some skin lesions may resolve spontaneously, therefore, treatment is focused on addressing any complications. Multiple medical and surgical interventions have been tried. Topical and intra-lesional corticosteroids have been used to stabilize rapidly enlarging lesions with limited success, however, have the potential to cause further skin atrophy. Surgical interventions including debridement and skin grafting are discouraged as in necrobiosis lipoidica trauma tends to induce the Koebner phenomenon.