According to cosmetic physician Dr John Mahony, of Peach Cosmetics, Sydney, "It is a symptom of something that's not functioning correctly in the body. The production of pigment which creates our skin tone, is triggered by an internal or external cause. The treatment should be directed to the cause."

Hormonal pigmentation
This type of pigmentation is related to oestrogen production, and is heightened by exposure to the sun.

"It may be that someone is on the Pill, or is pregnant," says Dr Mahony. "It appears as a milk-coffee stain across the forehead or across the upper lip or cheeks, and often as a vertical line along the belly."

Skin Peels