The cause of necrobiosis lipoidica diabeticorum (NLD) is unknown. A possible source is microangiopathy, which is a type of damage to the small blood vessels that occurs in some patients with diabetes. Hereditary also may be a factor in its development. People with a family history of diabetes appear to have an increased risk of developing NLD.

Several risk factors associated with diabetes make patients more susceptible to NLD and other skin disorders. These include:

• Impaired circulation. Reduced blood flow can damage the skin and other tissues by depriving them of oxygen. This can also suppress the immune system because white blood cells are unable to reach parts of the body.
  
  
• Hyperglycemia. High glucose (blood sugar) causes the body to lose fluid, allowing the skin to dry and crack. It also acts as a fuel for infections and helps infection spread to other parts of the body.
  
  
• Diabetic neuropathy. Autonomic neuropathy (damage to the autonomic nerves controlling involuntary functions) makes the body sweat less. Drier skin is more likely to crack. Peripheral neuropathy (damage to the nerves serving the limbs) impairs sensation and increases the chance of injury and the risk that wounds will go unnoticed and untreated.
  
  
• Hyperlipidemia (high levels of blood fats). High amounts of cholesterol and other fats in the blood can reduce circulation.
  
  
• High blood pressure (hypertension). This can worsen other diabetic risk factors.