Recognizing Diabetes Through Skin Manifestations: A VisualDx Guide

Acanthosis Nigricans

Acanthosis nigricans (AN) is thickening and darkening of the skin. It appears as rough, darkened, thick patches of skin, most commonly around the neck, armpits, and groin (although it may be seen in other body locations). This condition typically affects the left and right sides of the body equally and is asymptomatic.

AN is often associated with obesity. It can also be associated with diseases such as diabetes, autoimmune conditions, and hormonal disorders (such as polycystic ovarian syndrome.

• Treating the underlying medical condition causing the skin changes, such as losing weight or improving blood sugar control, will typically improve the skin changes, although it may take time.
• Skin treatment is not needed, but topical retinoids may be employed for cosmetic purposes.

Note: Development of this skin condition in the absence of diabetes, obesity, or a known hormonal disorder should prompt further evaluation. Rarely, this condition is caused by medications or may be a sign of malignancy.

Diabetic Dermopathy

Diabetic dermopathy, commonly known as shin spots, is the most common cutaneous finding in patients with diabetes mellitus (type 1 and type 2), presenting in up to 50% of diabetic patients. The etiology is unclear, although trauma is thought to be a causative factor.

Pink, red, tan, or dark brown patches appear on the lower legs, and sometimes the thighs, feet, and forearms. Older spots may appear white and scar-like. The condition does not itch or cause pain.

Treatment:

• Management of diabetes is the main concern, since diabetic dermopathy may be a cutaneous finding for microangiopathic complications.
• Otherwise, because lesions are asymptomatic, they do not require treatment.
• The use of moisturizers may help improve the appearance.

Diabetic Foot Ulcer

Diabetic ulcers (also known as neurogenic ulcers) are ulcerations on the pressure points of the foot. They are most commonly seen in individuals with long-standing diabetes (type 1 and type 2). The pathogenesis is primarily due to neuropathy but may be multifactorial (eg, neuropathy and peripheral artery disease).  Diabetic ulcers can be difficult to treat, frequently recur, and may result in significant morbidity in the form of loss of function and, often, loss of limb.

Prevention is key:

• Advise patients on daily foot inpsection, meticulous hygiene, and properly fitting shoes
• Offloading pressure is essential. This can be done through rest or adjusting the biomechanics of the foot through footwear, or through surgical correction.
• At every visit, remove calluses that have formed at pressure points on the feet, as there is a higher risk of developing an ulcer where a callus is present.

Treatment:

• Debridement is important and often requires little to no analgesia secondary to the neuropathy.
• The surrounding callus and devitalized tissue should be removed.
• The basic principles of wound care apply.

Bullosis Diabeticorum

Bullosis diabeticorum (BD), also known as diabetic bullae, occurs in about 0.5% of people with diabetes (type 1, type 2). It has an unknown pathogenesis, although an underlying microangiopathy may be involved. The lower extremities, including the toes, are most often affected, but the hands and forearms can also be involved and, rarely, the trunk.

Bullae (blisters) are noninflammatory and often develop rapidly. They are usually asymptomatic, although in some cases patients may experience mild burning or discomfort. Those with large bullae on the feet (particularly in older adults) may become unable to wear shoes, leading to a significant reduction in mobility and autonomy.

Management and disease course:

• There is no consensus on optimal treatment of BD.
• Bullae often resolve on their own without scarring, but recurrence is common, and new bullae can continue to form over a period of years.
• On the lower extremities, wound care is essential to prevent secondary infections.