Acanthosis Nigricans - Signs, Tests, and Misdiagnoses

Signs, Tests, and Misdiagnoses

Physicians can usually diagnose acanthosis nigricans by simply looking at a patient's skin. A skin biopsy may be needed in unusual cases. If no clear cause of acanthosis nigricans is obvious, it may be necessary to search for one. Blood tests, an endoscopy, or x-rays may be required to eliminate the possibility of diabetes or cancer as the cause.

Additionally acanthosis nigricans has similar visual characteristics (neck discoloration) with Casal collar, which is a symptom of pellegra (a nutrient deficiency disease, easily remedied with supplementation). In early stages of discoloration, it is hard for a non trained eye to distinguish one from the other.