Bullosis diabeticorum (BD), also known as bullous eruption of diabetes mellitus or diabetic bullae, occurs in about 0.5% of diabetic patients and has an unknown pathogenesis. The co-occurrence of neuropathy and nephropathy suggests an underlying microangiopathy. The bullae are noninflammatory and asymptomatic, and they typically develop rapidly.

BD develops in long-standing, uncontrolled diabetes, although there are reports of BD as the presenting sign of diabetes. Bullae often resolve on their own without scarring, but recurrence is common, and new bullae can continue to form over a period of years. The average age of onset is 55 years, and there is a 2:1 male-to-female ratio.