Pigmentation

Pigmentation is what happens when the melanocytes, the pigment cells in the skin, make more melanin in some areas than in others. The patch that results is light brown, deep brown or greyish depending on how deep the pigment sits, and that depth is the single fact that decides how easily it lifts.

Melasma is the commonest cause. It appears as symmetrical patches over the cheeks, forehead, upper lip and jawline, driven by sunlight, by oestrogen from pregnancy or the contraceptive pill, and by heat. Post-inflammatory pigmentation comes next: acne, eczema, an insect bite, a burn or a cosmetic procedure leaves a brown mark exactly where the skin was inflamed. Years of sun leave freckling and flat brown patches across the cheekbones, the forearms and the backs of the hands.

Sunlight drives all of them. Ultraviolet and visible light both stimulate melanocytes, so pigmentation treated without daily sun protection darkens again within weeks. Indian skin pigments readily and holds pigment for longer, so treatment here is gradual, and pushing it harder often makes the patch worse.

Your dermatologist makes the diagnosis from the pattern, its distribution and what came first. Symmetrical patches on the cheeks in a woman of childbearing age suggest melasma. A brown mark sitting exactly where a spot or a scratch used to be is post-inflammatory. Scattered flat brown patches on sun-exposed areas in an older person are sun damage.

A Wood's lamp, an ultraviolet light used in a darkened room, shows how deep the pigment lies. Pigment in the upper layer becomes more sharply outlined under the lamp and answers well to treatment; pigment sitting deeper in the dermis looks unchanged under it and is far more stubborn. That one test shapes what is realistic to aim for.

They will ask about pregnancies, the pill or other hormonal treatment, thyroid symptoms, medicines that make skin sun-sensitive, and what creams you have already used. Long unsupervised use of a strong steroid or an unlabelled fairness cream causes its own pigmentation and thinning, so bring the tubes with you. A biopsy is taken occasionally, where a patch fits none of the usual patterns.

There is no downtime from creams, and no quick result either. A prescription depigmenting cream is used nightly, the first visible change comes at six to eight weeks, and the fuller effect at three to four months. Mild redness and peeling in the first fortnight are expected.

A superficial peel leaves the face pink for a day and flaking on days three to five, and you can work throughout. Peels are given every two to four weeks in a course of four to six. Laser toning is done at low energy at three to four week intervals, with an hour or two of redness afterwards and nothing more.

What decides whether it lasts is daily sun protection and dealing with whatever caused it. A broad-spectrum sunscreen containing tinted iron oxide, reapplied through the day, is the most effective single part of the plan, and stopping it is the commonest reason pigment returns. Melasma fluctuates with sun and hormones for years, so maintenance treatment continues after the patch has cleared, and your dermatologist will set out what that involves at the review.