Dark skin on the neck is usually a result of something known as acanthosis nigricans. It's characterized by the National Institutes of Health as a skin condition that causes hyperpigmentation along the folds and creases of your body. The hyperpigmentation is usually accompanied by an abnormal thickening of the skin. Most people affected by this condition have an increased level of insulin within the body, as would be seen in diabetes, polycystic ovary syndrome and obesity.
Talk to your primary health care provider. It's important to properly diagnose the cause of the darkened neck skin, so make an appointment with your doctor as soon as possible. By diagnosing and subsequently treating the underlying cause of the condition, you can often see an improvement in the hyperpigmentation.
Apply a skin lightening cream directly on darkened skin. Until a cause is found, you can lighten your darkened neck skin with creams containing hydroquinone, a skin bleaching agent. Follow the directions on the packaging for best results.
The American Osteopathic College of Dermatology recommends using a topical retinoid. Retinoids typically treat acne, but are also known to lighten areas of hyperpigmentation. Follow the instructions provided by your doctor. Lactic, alphahydroxy or salicylic acids can all be used for this purpose as well.
Try losing weight, suggests the Mayo Clinic. If the acanthosis nigricans is caused by obesity, dropping the excess pounds can help regulate insulin levels, and thereby cause the dark skin around the neck to fade. Cutting back on your caloric intake while increasing physical exercise can often help you lose weight.
Change your diet. If the acanthosis nigricans is caused by diabetes, reducing your intake of sugars and starches may help fade hyperpigmentation. Before making any dietary changes, talk to a doctor or dietitian.
Invest in fish oil supplements. According to the Mayo Clinic, the dietary supplement shows promise in lightening skin affected by acanthosis nigricans.
Talk to your health care provider about a prescription for metformin. Women suffering from polycystic ovary syndrome can regulate their insulin levels with metformin, and consequently cause the darkened neck skin to fade.
Talk to a dermatologist about skin rejuvenation. Sometimes, the darkened and thickened skin can be improved with skin treatments, including dermabrasion and laser therapy. Both cosmetic procedures remove the surface layer of the skin, which promotes the growth of new skin cells closer in color and texture to the rest of your skin.