Melasma is a common acquired skin disorder that presents as a bilateral, blotchy, brownish facial pigmentation.

This form of facial pigmentation was previously called chloasma, but as this derives from the Greek meaning ‘to become green’, the term melasma (brown skin) is preferred.

Melasma is a common skin problem. The condition causes dark, discoloured patches on your skin.

It’s also called chloasma, or the “mask of pregnancy,” when it occurs in pregnant women. The condition is much more common in women than men, though men can get it too. According to the American Academy of Dermatology, 90 percent of people who develop melasma are women.

Medications and scented products — new targeted therapies for cancer and perfumed soaps, toiletries, and cosmetics may cause a phototoxic reaction to trigger melasma.

Researchers are examining the roles of stem cell, neural, vascular, and local hormonal factors in promoting melanocyte activation. 

Melasma is more common in women than in men, with an onset typically between the ages of 20 and 40 years. Melasma is most common in people who tan easily or have naturally brown skin (Fitzpatrick skin phototypes III, IV). It is less common in people with fair skin (Fitzpatrick types I, II) or black skin (Fitzpatrick types V, VI).

Melasma causes patches of discoloration. The patches are darker than your usual skin color. It typically occurs on the face and is symmetrical, with matching marks on both sides of the face. Other areas of your body that are often exposed to sun can also develop melasma.

Brownish colored patches usually appear on the: cheeks, forehead, bridge of the nose, chin.

It can also occur on the neck and forearms. The skin discoloration doesn’t do any physical harm, but you may feel self-conscious about the way it looks.

If you notice these symptoms of melasma, see your healthcare professional. 

They might refer you to a dermatologist, a doctor who specializes in treating skin disorders.

It isn’t totally clear what causes melasma. Darker-skinned individuals are more at risk than those with fair skin. Estrogen and progesterone sensitivity are also associated with the condition. This means birth control pills pregnancy, and hormone therapy can all trigger melasma. Stress and thyroid disease are also thought to be causes of melasma.

Additionally, sun exposure can cause melasma because ultraviolet rays affect the cells that control pigment (melanocytes).

Factors implicated in the development of melasma include:

Family history — 60% report affected family members

Sun exposure — ultraviolet and visible light promote melanin production.

Hormones — pregnancy and the use of oestrogen/progesterone-containing oral contraceptives, intrauterine devices, implants, and hormone replacement therapy, are implicated in one-quarter of affected women; thyroid disorders can be associated with melasma.