Melasma is a condition that causes tan or dark skin discoloration on the face. Because of it’s association with pregnant women, it is sometimes called the “mask of pregnancy.” Melasma is marked by a change in pigmentation that occurs primarily in sun-exposed areas of the skin. This condition is exacerbated by UV exposure, pregnancy, oral contraceptives, and certain anti-epilepsy drugs.
Melasma is more prevalent in women, especially in women of child-bearing age. However, up to 10% of cases have been reported in men. While all races are affected, there is predominance among Latinos and Asians. Melasma is more apparent during and after periods of sun exposure and less obvious in winter months, when sun exposure is lacking.
Melasma most commonly appears as large blotches of pigmentation (as opposed to freckles) in a centrofacial pattern involving the cheeks, forehead, upper lip, nose, and chin. Less common are the malar pattern, involving the cheeks and nose, and the mandibular pattern, involving the the sides of the cheeks and jaw line. Melasma also occurs on the forearms, but this is rare.
What are the Causes of Melasma?
Melasma is believed to be triggered by pregnancy, oral contraceptives, endocrine dysfunction, genetic factors, medications, nutritional deficiency, hepatic dysfunction, and other factors. The majority of cases appear to be related to pregnancy or oral contraceptives. The infrequency of melasma in postmenopausal women on estrogen replacement suggests that estrogen alone is not the cause.
In more recent cases, combination treatments using of en plus and ptational agents is are beiused in postmenopausal women., Melasma as been observed in some of these older women who did not present with the condition during their pregnanciesand melasmsure w be a stimulating factor in predisposed individuals. Although a few cases within families have been described, melasma should not be considered a hereditary disorder.
What is the Difference between Dermal and Epidermal Melasma?
Every case of melasma starts off in the epidermis, where melanocytes are actively producing pigment. A normal case of melasma can turn into dermal melasma if skin becomes over-irritated and inflamed. When this happens, it causes a temporary split between the dermis and epidermis. During this time, hyperpigmented cells can drop from the epidermis into the dermis. Once in the dermis, these cells become very resistant to topical treatment. This is one reason it is so important to avoid overly aggressive treatment of the condition.
Dermal melasma is particularly difficult to treat since active tyrosinase activity is only found in epidermal melanocytes. In dermal melanin, tyrosinase activity is not present; therefore dermal melasma is resistant to bleaching agents such as hydroquinone and kojic acid.
Treatments for Melasma
There are several treatment options available, most of which can be broken down into three categories: bleaching agents, exfoliants, and oral supplements. Bleaching agents are ingredients that actively work on suppressing melanin production – this is usually the most effective option for the majority of melasma cases. Exfoliants fade pigmentation by increasing cell turnover and encouraging the shedding of pigmented or damaged skin cells. Including exfoliants in a bleaching routine can improve and speed up results. In cases of dermal melasma, exfoliants (particularly mandelic acid) are the best choice since bleaching agents are ineffective.
As is always the case when treating any form of hyperpigmentation, sun protection is key. Always wear sunblock with broad-spectrum protection and with a minimum SPF of 30. Physical sunblocks with zinc oxide are preferable.