Melasma is a common pigmentation disorder that causes brown/gray blotchy patches on the face, particularly the forehead, cheeks, upper lip and chin. Sun exposure is the most important avoidable risk factor. Melasma is sometimes referred to as the mask of pregnancy, because it is often triggered by an increase in hormones in pregnant women, but can also occur with hormonal treatments (birth control pills and hormone replacement therapy), other medications (particularly newer cancer treatments), scented soaps, toiletries and cosmetics. Visible light has also been shown to contribute to melasma and abnormal skin pigmentation, particuarly in those with darker skin types. Visible light is emitted from indoor lights, computer screens, phones and tablets. The pigmentation is due to overproduction of melanin by the pigment cells, melanocytes, which is taken up by the keratinocytes and deposited in the dermis of the skin. Melasma is more common in females, those who tan well, and in Asian and Hispanic patients. Once it develops, it may last for many years and even decades.
Topical treatments are the treatments of choice. Year-round life-long sun protection is a must. Because of the effect of visible light as well as ultraviolet rays to abnormal pigmentation
I always recommend tinted, zinc containing sunblocks to my patients who suffer from melasma as the iron oxide present in tinted formulations helps to block the contribution of blue light to the problem. My favorites are Revision Intellishade Truphsyical and Elta MD Clear Tinted. This should be reapplied every 2 hours if outdoors during the summer months. Chemical sunscreens don't offer the same spectrum of protection for melasma, and in some instances, they may even trigger allergic reactions that can make melasma worse. Use only mild cleansers as irritant skin care products can induce pigmentation. Cosmetic camouflage (make-up) is also invaluable to disguise the pigment.
Tyrosinase inhibitors are the mainstay of medical treatment. The aim is to prevent new pigment formation by inhibiting the formation of melanin by the melanocytes. The application of 4% hydroquinone to the pigmented areas for 2–4 months is typically the most effective treatment. Azelaic acid can be applied twice daily long term and is safe in pregnancy. Kojic acid and liquourice extract are often included in over the counter formulations. Topical vitamin C can also inhibit abnormal pigmentation. Topical retinoids such as tretinoin and Retinol are a cornerstone of melasma treatment and normalise pigment production. Topical steroid ointments also reduce pigmentation and decrease the irritation associated with other topical treatments.
Combination treatment is typically more effective than treatment with a single agent. The most successful formulation has been a combination of hydroquinon, tretinoin and a moderate potency topical steroid with improvement in up to 80% of those treated.
Chemical peels, IPL (intense pulse light) and lasers can cause a paradoxical worsening of melasma by inducing inflammation and should only be used under the guidance of a Consultant Dermatologist.