Melasma is a brown patch of skin on the face that occurs due to sun exposure. These brown areas typically appear on the forehead, bridge of the nose, and cheeks. They may also appear on the forearms or any area that is commonly exposed to the sun. The condition is more common among people with darker skin, possibly because the melanocytes – the cells that produce pigment – are already more active than in people with light skin.

Melasma is not to be confused with a temporary sun tan or sunburn. The brown spots persist and often appear splotchy. Sometimes they do resolve on their own but they can also spread.

There is also a hormonal link to skin darkening. Women are far more likely to be affected than men. Men only represent about 10% of cases. It is very common during pregnancy and is sometimes referred to as the mask of pregnancy. Women taking oral contraceptives can also be affected.

This discoloration has no symptoms but many people dislike its appearance. There are many treatment options for melasma: microdermabrasion, laser lightening or fractional laser resurfacing, chemicals peels, and topical bleaching creams.

The results of treatment can be temporary. Brown patches can reoccur if a person continues to be exposed to the sun. Even a small amount of sunlight can cause the brown patches to return.

The best way to prevent melasma is to limit sun exposure. Ultraviolet (UV) light from the sun stimulates the melanocytes to produce more color. People should wear broad-spectrum sunscreen with an SPF of at least 30 every day. UV rays can penetrate clouds and windows so susceptible people should wear sunscreen at all times. Protective clothing, like wide-brimmed hats and sunglasses, should be worn to reduce the amount of exposed skin. Make-up with a white or yellow base can conceal brown patches.