Causes of Hyperpigmentation

To understand what’s behind hyperpigmentation (a fancy way to describe skin discoloration) you first need a crash course in melanin. Simply put, melanin is skin pigment, the substance that gives your skin its color. Dark-skinned people have more melanin than light-skinned people. Melanin, which is produced by cells called melanocytes, is also your body’s natural sunscreen, protecting the skin from ultraviolet light. Now, while it’s not always easy — or even possible — to pinpoint the specific cause of all hyperpigmentation (pigmentation disorders), there are a couple of pretty likely culprits.

Sun Exposure
Suspect number one: the sun! You can’t feel it happening, but ultraviolet rays stimulate melanocytes to produce more melanin. As more melanin is produced, the skin gets darker (hence, you get tan). Hyperpigmentation occurs when the body produces too much melanin, causing dark spots and patches to pop up or making existing freckles and age spots look even more pronounced.

Minimizing the chances and effects of hyperpigmentation means practicing smart sun safety: Limit the time you spend in the sun, wear protective clothing, including a wide-brim hat and sunglasses, and use a broad-spectrum, water-resistant sunscreen with a minimum SPF of 15 (though 30 or higher will offer better protection) year-round.

Inflammation
Another common cause of hyperpigmentation is inflammation, which typically occurs when skin is injured by a cut, scrape, burn, or chemical exposure or by acne, eczema, or psoriasis. It’s not the wound itself that’s the problem but rather what happens during the healing process. As the wound closes, you may experience postinflammatory hyperpigmentation, in which the area around the injury turns dark, like a scar. This discoloration can last for months or years or may even be permanent. Early treatment of the original injury is the best method of prevention, but there are steps you can take later on to try to fade the spot, such as chemical peels, microdermabrasion, and skin lighteners. Keep in mind that postinflammatory hyperpigmentation is more likely to affect people with darker skin than those with fair skin and that sun exposure will likely make matters worse.

Hormones
Any woman (and some men!) will tell you that hormones can cause all sorts of weird stuff to happen in your body. We’re particularly prone to hormonal fluctuations during pregnancy, when taking birth control pills or undergoing hormone therapy, or during certain illnesses. One such hormonally produced phenomenon is melasma, a common pigmentation disorder that typically occurs during pregnancy. Like postinflammatory hyperpigmentation, melasma (also known as the mask of pregnancy) is more likely to affect people with darker skin tones and tends to appear on the cheeks, nose, forehead, chin, and upper lip in brown or grayish-brown patches. Don’t panic if the mask pops up on you — melasma typically disappears after pregnancy (or the discontinuation of birth control pills). If it doesn’t, your dermatologist can treat it with topical steroid creams, skin lighteners, chemical peels, or laser treatments.

Another hormonal-based condition is Addison’s disease, a rare illness that interferes with the adrenal glands’ ability to produce certain hormones; hyperpigmentation is one of its multiple symptoms. Again, this disorder is rare, but do ask your doctor if you’re concerned about changes in your skin color.

Illness and Medication
Hyperpigmentation can also be a symptom of certain autoimmune and gastrointestinal diseases, as well as metabolic disorders and vitamin deficiencies. Plus, there are a number of medications known to cause hyperpigmentation, including certain hormone treatments, antibiotics, antimalarial drugs, antiseizure drugs, antiarrhythmics, and others. Talk to your doctor about the potential side effects of any drug you take, and be extra careful about sun exposure while taking medication.