Treating Children With Acanthosis Nigricans

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Public Health Update -- August 2002  

As a result of growing concern over rising rates of type 2 diabetes in children, the Texas Legislature in 1999 mandated that a pilot project be carried out to screen schoolchildren in nine counties along the U.S.-Mexico border for acanthosis nigricans (AN).  

AN is a hyperkeratinization of the skin and is a cutaneous marker associated with systemic disorders such as hyperinsulinema and insulin resistance. It also may serve as an indicator for risk of type 2 diabetes. AN is a condition that easily can be evaluated by means of a visual exam. It frequently manifests itself on the nape and sides of the neck, but also can be found on the axillae, elbows, knuckles, knees, and groin area. Hispanics, Native Americans, and African-Americans have a higher prevalence of these lesions and could be genetically predisposed and more sensitive to higher insulin levels.

At the direction of the Texas Legislature, The University of Texas System Texas-Mexico Border Health Coordination Office initiated Acanthosis Nigricans: The Education and Screening Project (ANTES) in September 1999. Under ANTES, children in Cameron, Hidalgo, Jim Hogg, Webb, Willacy, Starr, Zapata, El Paso, and Hudspeth counties are being screened for AN during hearing and vision screenings in grade 3 and again during scoliosis screenings conducted in grades 5 and 8 or grades 6 and 9. Children with AN are referred to their primary care physicians for follow-up.

In 2001, the legislature passed House Bill 2989 to extend the pilot to a full screening program in public and private schools along the border. In addition, the legislature mandated that:

  • The screening is to be conducted at the time of vision and hearing screenings;
  • The records are to be maintained at the school and are open to local health departments;
  • Each school is required to send to the coordination office a report on the screening status of children in the school;
  • If the child tests positive for AN, the person performing the screen must send a report to the parent or guardian that includes an explanation of AN and a statement on the need for further evaluation.

Testing for AN  

Physicians who receive a referral of a child with AN should conduct the following tests.

Fasting Blood Glucose  

The fasting plasma glucose (FPG) test and the oral glucose tolerance test (OGTT) are both suitable tests for diabetes; however, the FPG is strongly preferred because it is easier and faster to perform, more convenient and acceptable to patients, and less expensive. Fasting is defined as no consumption of food or beverage other than water for at least eight hours before testing.

An FPG level >126 mg/dL (7.0 mmol/L) or a two-hour postload value in the OGTT >200 mg/dL (11.1 mmol/L) are indications for retesting. Either test must be repeated on a different day to confirm a diagnosis.

Nondiabetic individuals with an FPG >110 mg/dL (6.1 mmol/L) but <126 mg/dL (7.0 mmol/L) are considered to have impaired fasting glucose (IFG), and those with two-hour values in the OGTT >140 mg/dL (7.8 mmol/L) but <200 mg/dL (11.1 mmol/L) are defined as having impaired glucose tolerance (IGT). Both IFG and IGT are risk factors for developing diabetes.

Normoglycemia is defined as plasma glucose levels <110 mg/dL (6.1 mmol/L) in the FPG and a two-hour postload value <140 mg/dL (7.8 mmol/L) in the OGTT.

(Source: American Diabetes Association. Clinical Practice Recommendations. Diabetes Care . 1999;22[suppl 1].)  

Fasting Plasma Insulin  

Fasting plasma insulin has been determined as a valid measurement of insulin resistance; the normal range is 2 to 12 µU/mL.

(Source: Stuart CA, Gilkison CR, Keenan BS, Nagamani M. Hyperinsulinemia and acanthosis nigricans in African Americans. J Natl Med Assoc . 1997;89:523-527.)  

Therapeutic Action  

There are no current pharmacological interventions available for AN. However, studies have shown that weight management and exercise can decrease fasting plasma insulin concentrations. As a result, risk associated with insulin resistance tends to decrease and AN markers tend to fade. Therapeutic action for the child should include weight management and exercise.

Recommendations for Weight Goals  

Children with a body mass index (BMI) greater or equal to the 95th percentile are considered overweight. Those between the 85th and 95th percentile are at risk of overweight.

A child with a BMI greater or equal to the 95th percentile should undergo an in-depth medical assessment because these children have a greater chance of maintaining obesity into adulthood. A BMI above the 95th percentile also is associated with elevated blood pressure, hyperlipidemia, and obesity-related disease and mortality.

A child whose BMI falls between the 85th and 95th percentile should be evaluated carefully, with particular attention given to secondary complications of obesity.

Prolonged weight maintenance allows for a gradual decline in BMI as a child grows in height and may be a sufficient goal for children. However, in the event of secondary complications, weight loss may be recommended.

(Source: Barlow SE, Dietz WH. Obesity evaluation and treatment: Expert Committee recommendations. Pediatrics. 1998;102[3]:E29.)  

Management of Individuals with AN  

AN is a clinical surrogate for hyperinsulinemia; therefore, no insulin exam is required. The management of individuals with AN is similar to the approaches used in caring for the newly diagnosed person with type 2 diabetes. Although blood glucose levels are usually normal in the young, an FPG and a hemoglobin A1c determination will confirm current glycemic status. The objective in managing clients with AN is to reduce the severity of insulin resistance, thereby lowering circulating insulin levels and sparing the pancreas. For the nondiabetic individuals, the goal is to prevent or delay the onset of diabetes.

(Source: Gilkison C, Stuart CA. Assessment of patients with acanthosis nigricans skin lesion for hyperinsulinemia, insulin resistance and diabetes risk. Nurse Pract . 1992;17[2]:26-43.)  

For more information or patient materials on acanthosis nigricans and ANTES, contact The University of Texas System Texas-Mexico Border Health Coordination Office, The University of Texas-Pan American, at (956) 381-3687, or log on to www.panam.edu/dept/tmbhco .

August 2002 Texas Medicine Contents
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