Is Acanthosis Nigricans a reliable indicator for risk of type 2 diabetes?

Acanthosis nigricans (AN) is a thickening and hyperpigmentation of the skin commonly found on the neck, axilla, or groin and is generally caused by hyperinsulinemia, a consequence of insulin resistance associated with obesity. Insulin resistance is a primary risk factor for the development of type 2 diabetes, hypercholesterolemia, and hypertension. Screening for acanthosis nigricans is controversial and not recommended by the Centers for Disease Control and Prevention; however, some states, such as Texas, are implementing AN screenings in schools to identify those children who are at highest risk for developing type 2 diabetes. With the current epidemics of obesity and diabetes, school nurses will see students in the health office with AN and should be knowledgeable about this skin condition and the association with hyperinsulinemia and obesity. The school nurse's role is to educate and assist students and their families in seeking appropriate medical advice based on current knowledge of risk factors. This article will explore the controversy associated with screening for AN and make recommendations for school nursing practice.

Assessment of patients with acanthosis nigricans skin lesion for hyperinsulinemia, insulin resistance and diabetes risk.

Acanthosis nigricans is a skin lesion characterized by thickening and apparent darkening of the keratin layer of the skin, usually on the neck and axillae. Recent studies reveal that this disorder is directly associated with hyperinsulinemia. A major implication of hyperinsulinemia is insulin resistance--a primary factor in the development of type II diabetes mellitus. Prolonged hypersecretion of insulin presumably leads to pancreatic exhaustion and subsequent glucose intolerance that can progress to type II diabetes. Prospective studies of individuals with acanthosis nigricans have shown very high prevalence rates of type II diabetes. Prevalence studies among adolescents have shown that the lesion appears early in life and is a common finding in some ethnic groups. These data suggest that acanthosis nigricans is an easily detected empirical marker for elevated risk of type II diabetes. The lesion can appear long before the onset of glucose intolerance. Thus, including acanthosis nigricans screening in a comprehensive disease-prevention program can help identify people at risk for type II diabetes prior to the actual onset of glucose intolerance, as well as individuals with undiagnosed diabetes. Interventions that reduce insulin resistance include weight loss and regular physical activity.