Melasma Causes and Treatment Options
I have two kids and during my second pregnancy I got melasma on my forehead. Obviously, I didn't like what I saw in the mirror and started to gather information about this condition, what are the reasons and how to treat it. And I thought I would share what I learned, so here it is.
What is Melasma
Melasma is a dark skin discoloration found on sun-exposed areas of the face. The most common locations are cheeks, upper lip, chin, and forehead are, but it can occasionally occur in other sun-exposed locations. Chloasma is a synonymous term sometimes used to describe the occurrence of melasma during pregnancy.
The good news melasma is not associated with any internal diseases or organ malfunction and by itself is a harmless skin condition.
Causes and Risk facrors
The precise cause of melasma remains unknown. The pigmentation occurs due to overproduction of melanin by the pigment cells, melanocytes.
- Genetic predisposition. A genetic predisposition is a major factor in the development of melasma. It is much more common in women than in men. More than 30% of persons who get melasma have a family history of dark skin discoloration. Identical twins have been reported to develop melasma, while other siblings under similar conditions did not (Hughes BR. Melasma occurring in twin sisters. J Am Acad Dermatol. Nov 1987;17(5 Pt 1):841.).
- Hormonal changes. A change in hormonal status may trigger melasma. It is commonly associated with pregnancy and called the "mask of pregnancy." Nearly 50% of pregnant women show some signs of the "mask of pregnancy". Estrogen, progesterone, and melanocyte-stimulating hormone (MSH) levels are normally increased during the third trimester of pregnancy. Birth control pills may also cause melasma.
- Sun exposure. Another risk factor is exposure to sunlight. Ultraviolet light from the sun, and even very strong light from light bulbs, can stimulate pigment-producing cells, or melanocytes in the skin. People with skin of color have more active melanocytes than those with light skin. These melanocytes produce a large amount of pigment melanin under normal conditions, but this production increases even further when stimulated by light exposure or an increase in hormone levels. All wavelengths of sunlight, including the visible spectrum, are capable of inducing melasma.
- Thyroid dysfunction. Thyroid dysfunction may also lead to development of melasma. One study found a 4-fold increase in thyroid disease in persons with melasma.
- Medications. Medications that sensitize the skin to UV radiation and certain cosmetics have been reported to cause melasma in rare cases.
Melasma may be very difficult to treat. The pigment of melasma develops gradually, and resolution is also gradual. Resistance and recurrences occur quite often and are certain if strict avoidance of sunlight is not rigidly heeded.
As melasma is a completely benign skin disorder with no untoward health consequences the treatment is only for cosmetic reasons. Many of treatments are very expensive, not curative and there is no guarantee that they will work at all. In fact, some treatments sometimes can even worsen the condition.
- Hydroquinone (HQ) Hydroquinone (HQ) is most commonly used. It is a hydroxyphenolic chemical that inhibits tyrosinase, leading to the decreased production of melanin. HQ can be applied in cream form or as an alcohol-based solution. Concentrations vary from a 2% concentration available in the United States without a prescription to a standard 4% concentration and even higher when compounded. Effectiveness is directly linked to concentration, but side effects also increase with concentration. It may reduce skin color too drastically, with some skin areas depigmented completely. If it is used inappropriately, hydroquinone can also cause a paradoxical and permanent darkening.
- Azelaic acid. Azelaic acid, is as effective as 4% HQ and superior to 2% HQ in the treatment of melasma. Unlike HQ, azelaic acid seems to target only hyperactive melanocytes and thus will not lighten skin with normally functioning melanocytes. The primary adverse effect is skin irritation. No phototoxic or photoallergic reactions have been reported. Azelaic acid also has antimicrobial effect, which may be beneficial for those with acne.
- Tretinoin. Tretinoin (Retin-A, Renova) is sometimes used alone or in combination with hydroquinone to treat melasma. It increases the turnover of skin cells, a process that helps reduce excess pigmentation. Tretinoin lightens melasma spots slowly, with improvement taking 6 months or longer. The retinoid is believed to work by increasing keratinocyte turnover and thus limiting the transfer of melanosomes to keratinocytes. The major adverse effect is skin irritation, especially when the more effective, higher concentrations are used. Temporary photosensitivity and paradoxical hyperpigmentation can also occur.
Other depigmenting agents used for melasma treatment include phenolic-thioether, kojic acid, ascorbic acid, flavonoid extracts, and meladerm.
- Chemical peels. Chemical peels have become a popular method of treating melasma. A number of studies have shown that treating melasma with superficial chemical peels (e.g. tretinoin peels, glycolic acid peels) is safe and effective. Whether superficial chemical peels versus bleaching agents alone actually hasten the resolution of pigment is debated. Studies comparing bleaching agents alone to the combination of bleaching agents and superficial chemical peels are ongoing and may help to resolve the debate.
- Dermabrasion and microdermabrasion. Dermabrasion and microdermabrasion should be undertaken very cautiously; damage to the melanocytes may increase pigment production and darken the melasma.
- Laser rejuvenation. Lasers that specialize in removing brown pigment are used to remove melasma.
- Sun protection - Extremely Important! Regardless of the treatments used, all will fail if sunlight is not strictly avoided. Sunscreens containing physical blockers, such as titanium dioxide and zinc oxide, are preferred over chemical blockers because of their broader protection. UV-B, UV-A, and visible light are all capable of stimulating melanogenesis.
- Make-up. Applying cosmetic camouflage is the safest method.
Some sources of information:
American Academy of Dermatology