About melasma (chloasma)
Melasma is a macular (flat) hyperpigmentation of the face that primarily affects women. The hyperpigmentation is symmetric on the face, but is sometimes patchy within a given area. Each macule has a distinct margin. Multiple factors contribute to melasma, specifically hormonal changes, such as occur during pregnancy or when taking birth control pills. It is sometimes called “the mask of pregnancy.” Melasma is exacerbated by exposure to ultraviolet radiation, such as from the sun. It is more common in dark skinned individuals.
With what can melasma be confused?
Freckles are smaller than the macules of melasma, are more numerous and have a wider distribution. Postinflammatory hyperpigmentation can follow an episode of dermatits
How is melasma diagnosed?
Patients usually seek medical care due to cosmetic concerns. It is diagnosed clinically. No biopsy or lab tests are usually necessary.
How is melasma treated?
Bleaching creams such as hydroquinone, available as a 2% preparation over-the counter or 4% by prescription, are frequently used. Tretinoin 0.1% (e.g. Retin A) can be used if other treatment fails. Combination bleaching creams containing hydroquinin, tretinoin, and a corticosteroid are available as well (e.g. Tri-Luma). Sunscreen must be used to prevent worsening of the condition. Chemical peels, such as glycolic acid or trichloroacetic acid, are sometimes used as well. Lasers have been used with variable results. These include the 1550-nm fractionated, Q-switched Nd-YAG, CO2, and long-pulsed and Q-switched alexandrite. Tranexamic acid, oral or topical, has also been shown to be helpful.
What is the prognosis for melasma?
With the conclusion or pregnancy or the discontinuation of birth control pills, and the avoidance of excessive sunlight exposure, melasma typically resolves. However, it may take months to years for normal pigmentation to return. Recurrence is common.
How is melasma prevented?
There is no certain way to prevent melasma. Avoidance of excessive sunlight during pregnancy or while on birth control pills is recommended, especially for dark skinned individuals.