Melasma

Melasma, also known as chloasma, appears as a blotchy, brownish pigmentation on the face that develops slowly and fades with time. The pigmentation is due to overproduction of melanin by the pigment cells, melanocytes.

Melasma / chloasma

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What causes melasma?

There is a genetic predisposition to melasma. Triggers include:

• Pregnancy – the pigment often fades a few months after delivery.
• Hormonal contraceptives, including oral contraceptive pills and injected progesterone
• Sun exposure
• Scented or deodorant soaps, toiletries and cosmetics – a phototoxic reaction
• Unknown factors, when it arises in apparently healthy, normal, non-pregnant women

Clinical features

Melasma usually affects women; only one in twenty affected individuals are male. It generally starts between the age of 30 and 40. It is more common in people that tan well or have naturally dark skin compared with those who have fair skin.

Melasma affects the forehead, cheeks and upper lips resulting in macules (freckle-like spots) and larger patches. Occasionally it spreads to involve the sides of the neck, and a similar condition may affect the shoulders and upper arms. Melasma is sometimes separated into epidermal (skin surface), dermal (deeper) and mixed types.

Treatment

Melasma can be very slow to respond to treatment, so patience is necessary. Start gently, especially if you have sensitive skin. Harsh treatments may result in an irritant contact dermatitis, and this can result in postinflammatory pigmentation.

Generally a combination of the following measures is helpful.

• Discontinuing hormonal contraception.
• Year-round sun protection. Use a broad-spectrum very high protection factor sunscreen of reflectant type and apply it to the whole face. Alternatively, use a make-up containing sunscreen.
• Use of a mild cleanser, and if the skin is dry, a light moisturiser. This may not be suitable for those with acne.
• Preventing new pigment formation. Bleaching creams inhibit the formation of melanin by the melanocytes. They include:
  • Hydroquinone 2-4%, for 2 to 4 months. This sometimes causes stinging and redness.
  • Azelaic acid can be used longterm, and is safe even in pregnancy. It may sting.
  • Kojic acid
  Sometimes a topical corticosteroid such as hydrocortisone is prescribed, which works quickly to fade the colour and has an additional benefit of reducing the likelihood of a contact dermatitis caused by other agents.
• Peeling off the pigment. Try:
  • Salicylic acid creams
  • Topical alpha hydroxyacids including glycolic acid and lactic acid, as creams or as repeated superficial chemical peels.
  • Topical retinoids, such as tretinoin. This works in several ways to improve skin colour, but can be hard to tolerate and might cause dermatiits. Do not use this during pregnancy.
  • Dermabrasion and microdermabrasion should be undertaken very cautiously; damage to the melanocytes may increase pigment production and darken the melasma.
  • Laser resurfacing – results may be unpredictable. Newer fractional lasers may prove safer.
• Destroying the pigment with pigment laser or intense pulsed light device – this is possibly the best treatment for a quick result but several treatments may be necessary.
• Applying cosmetic camouflage (make-up).

Results take time and the above measures are rarely completely successful. About 30% of patients can achieve complete clearance with a prescription agent that contains a combination of hydroquinone, tretinoin and a topical corticosteroid.

Unfortunately, even in those that get a good result from treatment, pigmentation may reappear on exposure to summer sun and/or because of hormonal factors.