A lifetime of sun exposure is bound to leave a few marks. Unfortunately, those marks tend to appear as dark spots and patches on the most visible parts of our skin. But the more we know about what causes them, the more we’ll be able to prevent and repair them.
Hyperpigmentation is a common condition in which patches of skin become darker, usually as a result of increased melanin production.
Melanin — the pigment responsible for skin, hair and iris color — absorbs the sun’s ultraviolet rays to protect the skin from overexposure. In doing so, those rays stimulate the melanocytes in the lower layer of the epidermis to produce more melanin. As more melanin is produced, the skin becomes darker. But too much melanin production can result in patchy discoloration on certain areas of the skin.
Age spots, also called liver spots or solar lentigines, are small, flat, gray, brown or black spots that appear on areas of the face, hands, arms and shoulders most exposed to the sun. While they are more likely to affect fair-skinned individuals and those with frequent or intense sun exposure, age spots are also common among adults 40 and older and those genetically predisposed to their development.
Although age spots are usually harmless, they can be lightened or removed if bothersome. Treatment options include prescription lightening creams, chemical peels, microdermabrasion, and laser or intense pulsed light treatments. However, a doctor should evaluate those that are dark or have changed in size or appearance for signs of melanoma, a serious form of skin cancer. To prevent age spots from forming, avoid the sun, wear protective clothing and use a broad-spectrum sunscreen daily with a minimum SPF of 30 or higher.
The sun isn’t the only cause of excess melanin production. Hormones can play a role, too.
Melasma, also known as chloasma or “the mask of pregnancy,” is a common skin condition characterized by large, brown patches of discoloration on areas of the face most exposed to the sun, such as the cheeks, nose, forehead, chin and upper lip. Although ultraviolet light is a risk factor, the hormones estrogen and progesterone can trigger an overproduction of melanin, causing discoloration on both the face and abdomen. Melasma is particularly common among women who are pregnant or are taking birth control pills or hormone replacement therapy. Women with darker skin are also more prone to the condition.
Although the discoloration usually fades after giving birth or stopping birth control pills or hormone replacement therapy, there are numerous treatment options available if yours doesn’t. These include skin lightening creams with hydroquinone, tretinoin, kojic acid, azelaic acid or retinol; chemical peels; and microdermabrasion. To prevent the condition from worsening, those with melasma should limit their exposure to sunlight and use a broad-spectrum sunscreen with SPF 50 or higher.
Sometimes, hyperpigmentation results from inflammation that occurs when the skin is injured by a cut, scrape, burn, chemical, or such skin conditions as acne, eczema or psoriasis. In these cases, the area around the wound becomes dark and scar-like during the healing process, resulting in temporary or permanent discoloration. Darker-skinned individuals and those who receive excess sun exposure are most likely to experience post-inflammatory hyperpigmentation. Although early treatment of the original injury is the best way to prevent it, chemical peels, microdermabrasions and skin lightening creams can be used to treat this type of hyperpigmentation.
Hyperpigmentation as Symptom or Side Effect
In some cases, however, hyperpigmentation may be a symptom of something else. Some autoimmune, gastrointestinal or metabolic disorders are known to cause hyperpigmentation. These include hemochromatosis, a hereditary condition that causes the body to absorb too much iron, and Addison’s disease, a rare disorder in which the adrenal gland produces too few hormones.
Certain medications are also known to cause hyperpigmentation. These include birth control pills and hormone treatments, antibiotics, antimalarial drugs, antiseizure drugs, antiarrhythmic drugs used to treat heart disease, and chemotheraphy drugs.
If you’re concerned about changes in skin color, consult your health care provider. It’s also important to talk to your provider about the potential side effects of any drugs you take, and protect yourself from sun exposure when taking medication.Photo of a patient with melasma by USP Hospitales/Creative Commons