Melasma, also know 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).
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.
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 typically 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.
On the face it tends to occur in three patterns;
- Both sides of the face, patches on the cheeks, forehead, nose, upper lip and chin (centro facial)
- Cheeks and nose (malar)
- Sides of the face, along the jaw line (mandibular)
Melasma is sometimes separated into epidermal (skin surface), dermal (deeper) and mixed types. Epidermal melasma which is more superficial tends to have well defined borders, is darker brown in colour and becomes highlighted under black light illumination. Epidermal melasma tends to respond better to treatment than dermal melasma which is lighter brown in colour. Mixed melasma which comprises a combination of light and brown patches improves with treatment but not as much as epidermal melasma.
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 irritation and even contact dermatitis, which 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 pigment cells (melanocytes). Options include hydroquinone, kojic acid and azelaic acid.
- Peeling off the pigment. Options include:
- 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 dermatitis. Do not use this during pregnancy.
- Microdermabrasion. This needs to be undertaken cautiously as damage to the melanocytes may increase pigment production and darken the melasma.
- Destroying the pigment with pigment laser or intense pulsed light device is possibly the best treatment for a quick result but several treatments may be necessary. Newer fractional lasers such as FRAXEL have been used with great success for more resistant cases.
- Applying cosmetic camouflage (make-up).
About 30% of patients can achieve complete clearance with a prescription cream that contains a combination of hydroquinone, tretinoin and 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.