Acanthosis nigricans associated with obesity, insulin-resistant states, and endocrinopathy (also known as "Acanthosis nigricans type III") is the most common variety of acanthosis nigricans, presenting with a grayish, velvety thickening of the skin on the sides of the neck, axillae, and groins.[1]:506-7 Acanthosis nigricans associated with endocrine dysfunction is more insidious in its onset, is less widespread, and the patients are often obese.[2]:676