Prevalence of acanthosis nigricans in an unselected population.

PURPOSE: The intent of this study was to determine, in an unselected population, the prevalence of the hyperinsulinemia-associated skin lesion, acanthosis nigricans.

SUBJECTS AND METHODS: The posterior neck of every child in the sixth and eighth grades of the public schools of Galveston, Texas, was personally examined by the investigators during a state-mandated school health survey. A total of 1,412 children were examined.

RESULTS: The data for each child examined included the absence or presence of acanthosis nigricans, height, weight, age, sex, and ethnic background. A subset of the children with the skin lesion also had fasting plasma insulin levels measured. Acanthosis nigricans was present in 7.1% of the 1,412 children examined. The skin lesion was equally distributed between boys and girls and was most common among children with severe obesity. The condition was present in two of 440 white non-Hispanics, 19 of 343 Hispanics, and 80 of 601 blacks examined. The fasting plasma insulin concentrations measured in some of these children and in previously evaluated subjects strongly correlate with the presence and severity of the acanthosis nigricans skin lesion.

CONCLUSIONS: This skin lesion is much more common than previously believed and has a dramatic ethnic predisposition. We conclude that the high prevalence of this skin lesion further suggests that insulin resistance and hyperinsulinemia, with all of their serious medical implications, are also highly prevalent.