Melasma is a very common patchy brown, tan, or blur-grey facial skin discolouration, usually seen in women in the reproductive years.

It typically appears on the upper cheeks, upper lip, forehead, and  chin of women 20 - 50 years of age. It is primarily related to external sun exposure , external hormones like birth control pills, and internal hormonal changes as seen in pregnancy. Most people with melasma have a history of daily or intermittent sun exposure, although heat is also suspected to be underlying factor. Melasma is most common among pregnant women, especially those of Latin and Asian decents. People with olive or darker skin, like Hispanic, Asian, and Middle Eastern individuals ,have higher incidences of melasma.

What causes melasma ?

The exact cause of melasma remains unknown. Experts believe that the dark patches in melasma could be triggered by several factors, including pregnancy, birth control pills, hormone replacement therapy (HRT and progestorone ) family history of melasma, race, and melasma , especially in individuals in individuals with general disposition to this condition. 

When melasma occurs during pregnancy, it is also called chloasma. Pregnant women experience increases oestrogen, progesterone, and melanocyte-stimulating hormone (MSH) levels during the second and third trimesters of pregnancy. Melanocytes are the cells in the skin that deposit pigment. However, it is thought that pregnancy-related melasma is caused by the presence of increased levels of progesterone and not due to oestrogen and MSH. Studies have shown that postmenopausal women who receive progesterone hormone therapy are more likely to develop melasma.

In addition, products or treatments that irritate the skin may cause an increase in melanin production and accelerate melasma symptoms.

People with a genetic predisposition or known family history of melasma are at an increased risk of developing melasma. Important prevention methods for these individuals include sun avoidance and application of extra sunblock to avoid stimulation pigment production..