Chloasma/ Melasma/Hyperpigmentation (over production of melanin)

What it is?

Melasma is a chronic skin disorder that results in symmetrical, blotchy, brownish facial pigmentation. It can lead to considerable embarrassment and distress.

This form of facial pigmentation is sometimes called chloasma, but as this means green skin, the term melasma (brown skin) is preferred.

Causes

The cause of melasma is complex. The pigmentation is due to overproduction of melanin by the pigment cells, melanocytes, which is taken up by the keratinocytes (epidermal melanosis) and/or deposited in the dermis (dermal melanosis, melanophages). There is a genetic predisposition to melasma, with at least one-third of patients reporting other family members to be affected. In most people melasma is a chronic disorder.

Known triggers for melasma include:

• Sun exposure and sun damage—this is the most important avoidable risk factor
• Pregnancy—in affected women, the pigment often fades a few months after delivery
• Hormone treatments—oral contraceptive pills containing oestrogen and/or progesterone, hormone replacement, intrauterine devices and implants are a factor in about a quarter of affected women
• Certain medications (including new targeted therapies for cancer), scented or deodorant soaps, toiletries and cosmetics—these may cause a phototoxic reaction that triggers melasma, which may then persist long term
• Hypothyroidism (low levels of circulating thyroid hormone)
• Melasma commonly arises in healthy, non-pregnant adults. Lifelong sun exposure causes deposition of pigment within the dermis and this often persists long-term. Exposure to ultraviolet radiation (UVR) deepens the pigmentation because it activates the melanocytes to produce more melanin.
• Research is attempting to pinpoint the roles of stem cell, neural, vascular and local hormonal factors in promoting melanocyte activation.”