How is Acanthosis Nigricans diagnosed?

The diagnosis of acanthosis nigricans is usually based on how your skin looks and where your skin is affected.  If the diagnosis is uncertain, you may have a skin biopsy.  When you have a biopsy, you are first given a numbing medicine.  Then your provider removes a small piece of skin.  The skin sample is sent to a lab.  At the lab the sample is examiined under a microscope.

In addition to the skin biopsy for acanthosis nigricans, additional tests for underlying problems should include blood pressure (BP) and endocrinology tests.

Blood tests and x-rays can also be used to find possible underlying causes for acanthosis nigricans.