Melasma also known as “Chloasma faciei” or the mask of pregnancy (when present in pregnant women) is a tan or dark skin discoloration. Although it can affect anyone, melasma is particularly common in women, especially women in the reproductive years between 20-50 years of age. The symptoms of melasma are dark, irregular well demarcated hyperpigmented macules to patches commonly found on the upper cheek, nose, lips, upper lip, and forehead. These patches often develop gradually over time. Melasma does not cause any other symptoms beyond the cosmetic discoloration. Rarely it spreads to involve the sides of the neck, and a similar condition may affect the shoulders and upper arms. Melasma can be classified into epidermal (skin surface), dermal (deeper) and mixed types.
Risk factors
• Dark skin – it is common in people of Asian and Hispanic origin.
• Hormonal – chloasma occurs commonly in pregnancy. Pregnant women experience increased estrogen, progesterone, and melanocyte-stimulating hormone (MSH) levels during the second and third trimesters of pregnancy. Also women taking birth control pills and hormone replacement therapy are more prone to develop melasma. The incidence of melasma also increases in patients with thyroid disease.
• Sun exposure – this is a well-established risk factor. Chloasma occurs in sun-exposed areas of the skin. Clinical studies have shown that individuals typically develop melasma in the summer months, when the sun is most intense.It turns lighter in winters.
• Genetics – 30% of patients report a positive family history and identical twins with chloasma have been reported.
• AIDS – one study reported a group of AIDS patients who developed chloasma-like hyperpigmentation of the face.
• Other rare causes of melasma include allergic reaction to medications( like antiseizure drugs), cosmetics, deodorant soaps and toiletries.
Diagnosis
Diagnosis is simply done by skin examination.
A special lamp [Wood’s lamp] that gives off ultraviolet light may be used. It allows to see patterns and depth of skin discoloration more clearly.
Medical history will help to determine any factors that may have caused the disorder.
Prevention
Avoiding the exposure to sun and using of sunscreen .
Avoid irritating the facial skin- No strong soaps or abrasive cleaners – use only a mild soap or cleanser for washing.
Increase intake of foods high in folic acid, dark green leafy vegetables, wheat germ, asparagus, broccoli, potatoes, whole grains, fruits and vegetables.
Treatment
The discoloration usually disappears spontaneously over a period of several months after giving birth or stopping the oral contraceptives or hormone replacement therapy.
Treatments to hasten the fading of the discolored patches include:
• Topical depigmenting agents, such as hydroquinone(HQ) -2% to 4%. HQ is a chemical that inhibits tyrosinase, an enzyme involved in the production of melanin.
• Tretinoin, an acid that increases skin cell (keratinocyte) turnover. This treatment cannot be used during pregnancy.
• Azelaic acid(20%), decreases the activity of melanocytes.
• Facial peel with alphahydroxyacids or chemical peels with glycolic acid.
• Laser treatment.
Prognosis
Lesions resolve slowly. Continued exposure to sunlight tends to hamper treatment and lead to recurrence. Resolution will also take longer in patients with extensive dermal melanin compared to those in whom pigmentation is mainly in the epidermal layer. There is no potential for malignant transformation.
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