Hyperpigmented Plaques of the Alar Crease: An Unusual Presentation of Acanthosis Nigricans.

Although acanthosis nigricans of the posterior neck and intertriginous areas is common, acanthosis nigricans of the supra-alar creases is rare. We present the case of an obese 16-year-old African American boy with hyperpigmented plaques along the supra-alar creases of his nose. Clinicians should be aware of this rare manifestation, because newly diagnosed acanthosis nigricans should prompt examination for insulin resistance.