[Acanthosis nigricans: epidemiologic study of 69 cases].

BACKGROUND

Acanthosis nigricans is a well-defined skin disorder with a distinctive appearance and an elective topography to the flexural areas that facilitate its diagnosis. In Tunisia, apart from isolated reports of malignant AN, few epidemiologic data are available.

AIM: In order to describe the characteristics of this affection, we conducted a retrospective study in the area of Tunis over a 12-year period.

METHODS

Retrospective study of all the cases of AN seen in the dermatology department of Habib Thameur teaching hospital between 1991 and 2003, including the cases coming from the north and of the centre of Tunisia.

RESULTS

Sixty-nine cases were recorded with a sex-ratio H/F of 0.17. The average age was 24.1 years (extremes of 3 and 66 years) and 57.9% of the patients were aged between 9 and 22 years. The neck (98.6%) and the axillae (75.4%) represented the most common localizations. All the patients presented a benign AN, comprising 51 cases of pseudo-AN, 11 cases of AN associated with endocrine diseases, 5 cases of familial AN and 2 cases of AN associated with an auto-immune disease. Local treatments associated an hypocaloric diet (AN with obesity) were recommended with a light improvement after 3 months an average follow-up.

CONCLUSION

The frequency of the AN is probably underestimated because of the usually asymptomatic character of this affection. AN constitutes a double cutaneous marker, being able to reveal either an hyperinsulinemia constituting a cardiovascular risk factor or an ignored subjacent neoplasm engaging the vital prognosis.