Learn about what causes acanthosis nigricans, how it’s treated, and how you can naturally lighten dark skin patches at home
Acanthosis nigricans is a skin disorder characterized by dark patches of skin that have a thick, velvety texture. Patches are usually seen in the folds of the body, such as the armpits, groin, neck, elbows, knees, knuckles, lips, palms, and soles of the feet.
Acanthosis nigricans is not a disease but a sign of other underlying conditions, typically occurring in people who have diabetes or who are obese. Causes may include:
- High levels of insulin: Acanthosis nigricans can be caused by high levels of insulin in the blood associated with obesity or polycystic ovarian disease.
- Medications: Certain medications such as oral contraceptive pills, hormone therapy, thyroid medications, bodybuilding supplements, and chemotherapy drugs can increase the risk of acanthosis nigricans.
- Other possible causes:
- Stomach cancer
- Adrenal gland disorders (Cushing syndrome)
- Pituitary gland disorders
- Low thyroid hormone levels
- High doses of niacin
How is acanthosis nigricans treated?
Treatment of acanthosis nigricans involves treating the underlying cause, along with cosmetic treatments to reduce the appearance of dark patches.
Doctors may recommend starting a weight loss program and discontinuing or changing certain medications. They may also prescribe medications to treat underlying conditions, for example medications to lower insulin levels if the condition is caused by high insulin levels.
While the hyperpigmentation usually fades once the underlying condition is treated, there are several cosmetic treatments (medical and home remedies) that can help the patches disappear faster.
Medical treatment to treat acanthosis nigricans includes medical facials, laser treatments, prescription topical products, chemical peels, and microdermabrasion.
How to lighten dark patches at home
Alpha hydroxy acids (AHAs) and beta hydroxy acids (BHAs)
Regular exfoliation with AHAs and BHAs can help make the skin smoother, softer, and brighter. AHAs and BHAs help reduce pigmentation and fine lines, remove excessive sebum and dead skin cells, unclog pores, and gently remove existing blackheads and whiteheads. They also cleanse the skin of dirt and makeup. Glycolic acid and lactic acid are the most popular AHAs, and salicylic acid is the most popular BHA.
Since overdoing it can irritate the skin and cause you to break out, doctors recommend using AHAs and BHAs every other day or 2 times a week. Always do a patch test first, and start with a lower strength (1%-2%) serum and gradually increase the strength if your skin tolerates it well. If you experience an allergic reaction, discontinue use.
Serums containing vitamins C and E also help with skin pigmentation and keep the skin hydrated, which helps increase cell turnover. Certain acids and vitamin C can cause increased sun sensitivity and should only be applied at night.
Topical retinoids
Retinoids are highly effective in removing stubborn pigmentation and also help improve skin texture. However, retinoids should be used with caution, since they can cause visible peeling, dryness, burning, redness, and increased sun sensitivity as the skin adjusts, which may take 4-6 weeks.
You can start applying low-strength over-the-counter retinoids 2-3 times a week, gradually increasing the strength and frequency of usage. Higher strengths of retinoids require a doctor’s prescription.
Homemade masks
Natural ingredients can be applied to the skin 2-3 times a week:
- Yogurt, lemon, and gram flour mask: The mask may be applied over problem areas, left on for 10 minutes, and then washed off.
- Yogurt is rich in nutrients and lactic acid, a naturally occurring exfoliating agent.
- Lemon contains vitamin C that can reduce pigmentation. You may need to dilute the lemon juice (2 parts juice and 1 part water) before adding it to the mask.
- Gram flour helps thicken the mask, giving it a paste-like consistency. Gram flour also acts as a natural exfoliating scrub that is gentle on the skin, improving skin texture and reducing hyperpigmentation.
- Papaya, banana, lemon, honey, and rice flour mask: These ingredients contain vitamins and minerals that can reduce pigmentation, improve skin texture, and nourish the skin. They may be mashed into a paste, applied all over the affected areas, and washed off after 10 minutes.
Diet, nutrition, and hydration
A healthy, balanced diet rich in fruits and vegetables and adequate hydration (8-10 glasses of fluids per day) are important for skin health because they promote skin cell turnover. You may also consider taking nutritional supplements, especially vitamin C, vitamin B, vitamin E and omega-3 fatty acids.
Sun protection
Sun damage can trigger other pigmentation problems and leads to premature aging. Excessive sun exposure is also a risk factor for skin cancer. Without protection from sun damage, medical and natural treatments to care for the skin are futile.
One of the best ways to protect the skin from sun damage is regular application of sunscreen. The American Academy of Dermatology recommends using a sunscreen that provides broad-spectrum UVA and UVB protection, SPF 30 or higher, and that is water resistant. Sunscreen should be reapplied every 3-4 hours and used daily throughout the year, including colder seasons and cloudy days.