Makindo Medical Notes

Necrobiosis lipoidica diabeticorum (NLD) is a rare, chronic skin disorder strongly associated with diabetes mellitus. It presents as well-demarcated, atrophic plaques, typically on the shins. About 0.3–1.2% of patients with diabetes develop NLD.

🔎 Introduction

• First described in 1929 by Oppenheim.
• Occurs in both type 1 and type 2 diabetes, more common in women (3:1).
• Although associated with diabetes, it can occur in non-diabetics.

⚙️ Pathophysiology

• The exact mechanism is unclear but involves microangiopathy (small vessel damage) similar to diabetic retinopathy/nephropathy.
• Collagen degeneration, granulomatous inflammation, and lipid deposition contribute to characteristic lesions.
• Immune-mediated processes may also play a role.

🩺 Clinical Features

• Lesions usually on the anterior shins, less commonly on arms, trunk, or scalp.
• Start as small red papules → enlarge into yellow-brown plaques with central atrophy and telangiectasia.
• Edges are raised and violaceous.
• Ulceration may occur after trauma, which can be painful and slow to heal.
• Most lesions are asymptomatic, but cosmetic concerns are common.

📊 Associations

• Strongly linked to diabetes mellitus (especially poorly controlled).
• More common in women and adults.
• May coexist with other diabetic complications such as retinopathy and nephropathy.

🧪 Investigations

• Clinical diagnosis is usually sufficient.
• Biopsy if uncertain: shows necrobiosis of collagen, palisading histiocytes, plasma cells, lipid deposits, thickened blood vessel walls.
• Check glycaemic control (HbA1c, fasting glucose).

💊 Management

• Optimise glycaemic control – important but lesions may persist despite good control.
• Topical or intralesional corticosteroids – may reduce inflammation at lesion edges.
• Topical tacrolimus or PUVA therapy sometimes helpful.
• Aspirin or pentoxifylline may improve microcirculation.
• Ulcerated lesions require wound care, infection control, and sometimes surgical intervention.
• Patients should be advised to avoid trauma to affected areas.

⚠️ Complications

• Ulceration – most common complication.
• Secondary bacterial infection.
• Rarely, squamous cell carcinoma can arise in chronic ulcerated lesions.

📌 Prognosis

• Chronic, relapsing course – lesions often persist for years.
• May remain stable, improve, or rarely resolve spontaneously.

📚 References

• DermNet NZ – Necrobiosis lipoidica
• NCBI Bookshelf – Necrobiosis Lipoidica
• NHS UK – Necrobiosis Lipoidica