Introduction

Acanthosis nigricans is the medical term for darkened, thickened patches of skin that usually develop in the armpit and around the groin and neck.

It's not a condition in itself, but can be a sign of an underlying health problem. These underlying conditions aren't usually serious, although occasionally acanthosis nigricans can besign of Predictive genetic test for cancer risk genes .

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Medically Reviewed by a doctor on 30 Nov 2016