Melasma is a skin condition where brown patches develop on the skin. It more commonly affects the face, and other parts of the body where the skin is exposed to the sun (i.e. the arms, chest and neck). On the face, melasma affects the forehead, cheeks, chin and the nasal bridge. Other than the appearance of patches on the skin, there are no other signs or symptoms of melasma. Melasma can affect the more superficial part of the skin (called the epidermis) or the deeper layer of the skin (the dermis). In some people, there is a mixture of both dermis and epidermis involvement, and this is called mixed melasma.
Causes
Melasma predominantly affects women; however, it is possible for men to be affected by melasma. The exact cause of melasma is unknown, but it is believed to be due to over-activity of the cells in the skin that make melanin (the pigment that gives skin its colour). These specialised cells are called melanocytes. Melasma is more common in people with darker coloured skin, possibly because the melanocytes in people with dark skin are more active than in people with lighter skin tones. There is also a genetic component to melasma, as people who have had a family member with melasma are more likely to experience melasma themselves.
It is common for an event to trigger the start of melasma. Some triggers for melasma that have been reported include:
- Hormonal changes & pregnancy
- Sun exposure
- Thyroid Disease
- Some make-up and cosmetic products
- Certain medications (contraceptive pills, anti-epileptic medications)
Hormones
One theory on the cause of melasma is that oestrogen and progesterone, the two female sex hormones, cause the melanocytes to become over-active and produce more melanin when there is exposure to the sun. This theory explains why melasma is much more common in women than in men. It also explains why women can develop melasma during pregnancy, because the levels of oestrogen and progesterone are much higher during pregnancy. Melasma brought on by pregnancy is called chloasma.
Another hormone that has been implicated in melasma is called Melanocyte Stimulating Hormone (MSH). MSH is also higher in pregnancy than normal and may contribute to chloasma. MSH is made by a tiny gland in the brain, called the pituitary gland. MSH stimulates the melanocytes to make more melanin and make the skin appear darker.
Sun exposure
The sun contains ultraviolet (UV) rays that also act to stimulate the melanocytes to make more melanin. This is the most common trigger for melasma, and small amounts of sun exposure can cause melasma to re-appear after it has faded. Due to the importance of sun exposure in the condition, melasma is much more common in the summer months.
Ethnicities
Certain ethnic groups are more likely to suffer from melasma than others, primarily due to the pigmentation characteristics of the skin. People of the following backgrounds are at an increased risk:
- Latin/Hispanic
- North African
- Indian
- African-American
- Middle Eastern
- Mediterranean
- Asian
Prevention of Melasma
One of the most important things to do in terms of preventing melasma is to take precautions surrounding exposure to the sun. This is especially important for people who have a known family history of melasma. Wearing high SPF sunscreen, wearing a hat, sunglasses and long clothing are important in order to limit the amount of exposure of the skin to the sun’s UV rays. Another prevention measure that may be taken by women who have a family history of melasma is to use non-hormonal contraceptive methods. Hormonal options, such as the contraceptive pill, can increase the likelihood of developing melasma.
Diagnosis
Skilled doctors can diagnose melasma on the pattern of pigmentation on the face alone. Use of a specialised lamp (a black light/Wood’s lamp) can also help to make a diagnosis of melasma. In some cases, a biopsy may be ordered, where a small sample of tissue is taken and analysed under a microscope to confirm the diagnosis.
Treatment
Whilst some treatment options for melasma exist, the treatments are not always effective in all patients. Sunscreen and sun precaution measures are the most important starting point in the treatment of melasma. A few creams can be used to help lighten the pigmentation, although they do not always return the darkened patches to the original skin tone.
Hydroquinone is one agent contained in some ointments that can help lighten the colour of the patches in the skin. It can also be incorporated into a sunscreen in some preparations. Sometimes a side effect of this treatment is that the patches of skin may actually become darker; and if this is the case, the treatment should be stopped. It can also cause irritation of the skin, so is a good idea to test a tiny amount of cream on a small, unaffected area first. This formulation is applied twice a day for about 3 months or so.
Another agent that is used in ointments is called tretinoin. This cream also helps to lighten the patches of affected skin. It can cause skin irritation, so it should also be tested before applying to the skin, and should not be used over extensive periods.
If the skin does not respond to these treatments, there are a few more options for melasma. One is a chemical peel, where a chemical solution is applied to the skin causing the upper layers of dead skin to peel off. It may help people with moderate or severe melasma that has not responded to bleaching treatments. There are also a few laser treatment options, but these are seldom recommended because it is common to relapse after undergoing treatment.
In people with chloasma, the majority of cases will resolve spontaneously within a year. Some cases will improve, and not resolve completely. In subsequent pregnancies, melasma may become more obvious.
If you have any questions or concerns about melasma facial pigmentation contact your local doctor, who will arrange for you to see a dermatologist. Contact Us Today!
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