I noticed the dark lines on his neck and this is known as Acanthosis Nigricans (AN), characterized by dark, velvety, thickened skin in creases like the neck, a precursor to Type 2 diabetes. These "lines" aren't true wrinkles but hyperpigmented patches with accentuated skin texture, sometimes with skin tags, and they don't wash off. Better diabetes control through diet, exercise, and weight management can improve the skin's appearance.
