Lately the dermatological symptoms of diabetes have been receiving greater attention in clinical settings because early diagnosis of risk results in preventive strategies, which can delay or halt the onset the disease. According to the American Diabetes Association, one-third of the population will present with a skin disorder associated with diabetes. Acanthosis nigricans is one of these skin disorders.
Symptoms
Acanthosis nigricans is characterized by the appearance of dark, velvety patches of skin that can often be mistaken for poor hygiene. These patches are raised above the normal skin level and are usually found on the nape and sides of the neck, and in skin folds, such as the armpit or groin areas. In some cases, the dark, discolored patches may also appear in other areas, including the knees, elbows and knuckles.
Causes
In individuals with type 2 diabetes, or those who are prediabetic, one of the first physiological changes is related to the hormone insulin. In these individuals, the body cannot recognize the insulin it produces or use it properly, a condition called insulin-resistance. As a result, the body pumps out more insulin, causing the insulin levels in the blood to rise above normal. This increase in insulin leads to a cascade of inflammatory signals in the body that leads directly to changes in the skin leading to acanthosis.
Prevention
One of the leading causes of disturbances in insulin regulation is weight gain. The inflammation associated with weight gain triggers the pathway of insulin-resistance leading to most symptoms associated with diabetes, including acanthosis. Weight loss through diet and exercise is the most effective way to reverse acanthosis and stop the progression of diabetes.
Treatment
In cases where diet and exercise are insufficient, pharmacological approaches to treatment may be indicated. Treating the underlying insulin resistance treats acanthosis. Drugs used to improve insulin sensitivity in diabetes, such as metformin and rosiglitazone, can be used to reduce acanthosis symptoms. The dark pigmentation and scarring of skin in extreme cases can also benefit from the addition of oral or topical retinoid drugs, which are used to treat acne and acne scars.
Considerations
There are genetic factors in prevalence of acanthosis in diabetic populations. Acanthosis is present to a greater extent in Native Americans, followed by African Americans, Hispanics, and Caucasians. This prevalence appears to be related to the increased diabetes risk in these populations. Acanthosis is not a predictor of diabetes, but rather, a warning of potential risk for the condition. In rare cases, acanthosis can be cancerous, and therefore it should be taken seriously not just as a symptom but also as an independent skin disorder.
References
- Centers for Disease Control and Prevention: National Diabetes Fact Sheet, 2007
- American Diabetes Association: Living With Diabetes--Skin Complications
- "American Journal of Clinical Dermatology"; Acanthosis Nigricans Associated With Insulin Resistance--Pathophysiology and Management; Hermanns-Lê et al.; 2004
- "Dermatology Online Journal"; Acanthosis Nigricans: A Practical Approach to Evaluation and Management; Higgins et al.; 2008
