Description

• Necrobiosis lipoidica (NL) is a granulomatous skin disease.
• Presents with red-brown papules that develop into plaques with violaceous or red-brown raised borders and atrophic, yellow-brown, telangiectatic centers
• Most commonly occurs on the pretibial area
• Ulceration is the most common complication.
• Historically associated with diabetes mellitus (DM), although this association is now questioned
• Management is difficult but includes medical and/or surgical treatment.

Epidemiology

• 0.3–1.2% of DM patients have NL (1).
• 15–65% of NL patients are reported to have DM (1).
• Female > male (3:1) (1)
• Average age of onset is the 3rd or 4th decade of life; may also occur in children (rare) and the elderly

Etiology and Pathophysiology

• Exact etiology remains unknown.
• One theory suggests that NL results from microangiopathy which is also associated with DM (1).
• Other theories include immunoglobulin deposition, impaired neutrophil migration, collagen abnormalities, inflammatory processes such as antibody-mediated vasculitis and trauma (1,2).
• Pathophysiology demonstrates collagen degeneration evolving into granulomatous inflammation with dermal and subcutaneous inflammation.
• Fatty deposition and endothelial wall thickening occur later, secondary to inflammation.

Risk Factors

• DM
• Trauma

General Prevention

There are no known data on prevention.

Commonly Associated Conditions

• Older studies have reported >60% prevalence of diabetes in NL patients, whereas newer studies have reported only 15%; therefore, what was previously thought to be a strong association is now being called into question; diabetics with NL may have a higher incidence of microvascular complications such as retinopathy, neuropathy, and nephropathy (1,3).
• NL may also be found with thyroid disorders, sarcoid, inflammatory bowel disease, and rheumatoid arthritis (1,3).