Rapid Review: Acanthosis Nigricans

Reviewed February 2024

Acanthosis Nigricans

• Risk factors: obesity, diabetes, rarely malignancy
• PE: thickened, velvety, darkly pigmented plaques on the neck or axillae
• Screen for diabetes and treat underlying disorder

Sample question:

A 39-year-old woman presents for evaluation of darkening areas on the back of her neck. She has a history of hypertension and hypothyroidism. Her current medications include oral contraceptives, levothyroxine 125 mcg, and lisinopril 10 mg. Her vital signs are body mass index of 35.2 kg/m2, temperature of 97.7°F, blood pressure of 140/98 mm Hg, heart rate of 97 bpm, respiratory rate of 18/minute, and oxygen saturation of 100%. Physical exam reveals hyperpigmented plaques with a velvety appearance on the back of her neck and her bilateral axilla. Her hemoglobin A1C is 5.5 mg/dL. What component of the patient’s history is the most commonly associated with her skin findings?