"Regardless of gender, melasma can appear on sun-exposed areas of the face as a flat, distinct area of discoloration. These dark patches typically appear on the forehead, cheeks and chin in a symmetrical fashion."1

Vital Pigment: Melanin

To understand disorders of pigmentation, it is important to understand the fundamentals of human skin color and its protective function. Despite the tremendous range in human skin color, all of the variations we see are due to the presence of a pigment known as melanin. Stemming from the Greek word melas, meaning black, melanin is composed of two forms: the brownish black eumelanin and the reddish yellow pheomelanin. Studies have shown that melanin production gives rise to skin color that ultimately protects the individual from both vitamin D deficiency and solar radiation. Thus, our ancestors' unique complexions evolved to be dark enough to protect DNA from ultraviolet (UV) damage and light enough to allow ultraviolet B (UVB) to penetrate for vitamin D synthesis, depending on the amount of UV rays available.2 That is why melanin is so vital to our health – too much and we risk vitamin D deficiency and disease; too little and we risk skin cancer and death.
Skin color is beyond skin deep. The same embryonic tissue that gives rise to the neurons of the brain also gives rise to the melanin found in our skin, eyes and hair. Melanin production in the skin, known as melanogenesis, is under the influence of various internal and external factors. In addition to UV rays, hormones and inflammatory signals can stimulate the melanocyte to increase the melanin production and/or increase transfer of melanin to keratinocytes. In both cases, the result is a darkening of the skin. Since so many key factors affect skin pigmentation, the changes seen can be transient (during pregnancy), permanent (intrinsic aging), environmental (upon UV exposure), and external (certain drugs or medications).3 Even though melasma was thought to be a pregnancy-related and/or contraceptive-related disorder in the past, new research shows that for many people, including men, it is a chronic disorder that lasts for decades.

Melasma: A New Understanding

Historically, melasma was considered a disorder of hyperpigmentation in women who were experiencing hormonal changes. Today, we know that it is more complicated than that. While we have yet to find the exact cause, current theories suggest that hormones, UV exposure and genetics are all major influencers of the disorder. Melasma is more common in darker skin types, particularly Fitzpatrick skin types III and IV, and is estimated to affect 8.8 percent of Hispanic females in the United States and about 40 percent of Southeast Asian women.1 The relatively new finding that this condition runs in families stems from studies on different ethnic populations. For example, 55 percent of pregnant Iranian women reported having a family member with melasma, while 70 percent of Puerto Rican women reported the same family link.4 Interestingly, melasma runs in families regardless of whether a man or woman inherits the disease. One study showed that 70 percent of Latino men with melasma also had a family member with melasma.1 Clearly, there is a genetic component that is not exclusive to women.

In many people who get melasma without the hormonal component, a combination of factors (including family history, age and UV exposure) can trigger the disease. Melasma usually occurs in sun-exposed areas where UV rays have either triggered or worsened pigmentation. Under the microscope, melasma skin can even resemble photodamaged skin with hallmarks such as solar elastosis.6 Inflammation is likely to play a large role in sun exposed skin considering that UV stimulated inflammatory signals, including cytokines and the peptide alpha-melanocyte-stimulating hormone (α-MSH), can also trigger melanogenesis. With UV exposure, there is a direct and indirect way of stimulating the melanocyte to produce more pigment.1,6 As new research emerges, we may find that infrared, or even visible light, may be a triggering factor for those susceptible to getting melasma. Since sun exposure is a critical factor in the development of melasma for both men and women, educating the client on appropriate sun protection as part of their regular skin care regimen is important advice to give them.

"While melasma was thought to be a pregnancy-related and/or contraceptive-related disorder in the past, new research shows that it can be a chronic Disorder that lasts for decades."

Hormonal Triggers

Pregnancy is a time when you can expect the unexpected. In addition to the variety of skin changes a woman can experience during pregnancy, some degree of hyperpigmentation affects nearly all women. However, in some women the level of hyperpigmentation is noticeably increased. Melasma generally occurs in 10 to 15 percent of pregnant women and in 10 to 25 percent of women taking oral contraceptives.6 For decades, melasma was known as the mask of pregnancy, with the assumption that it must be caused by an increase in female hormones due to pregnancy or birth control pills. The reality is that we still do not clearly understand the hormonal link to melasma.
Melasma skin is more estrogen-responsive than non-melasma skin.1,6 Nevertheless, other hormones involved in a woman's menstrual cycle and pregnancy, including progesterone and α-MSH, can also stimulate pigmentation. Just as melasma skin is more estrogen-responsive, it has also been shown to be more progesterone-responsive than normal skin.9 The notion that oral contraceptives can lead to skin changes is not a new one. In 1967, dermatologist Sorrel Resnik, M.D. showed that melasma developed in women as a direct result of taking oral contraceptives.8 Today, several forms of hormonal contraceptives are available including combination oral contraceptives, progestin-only oral contraceptives, combination patch contraceptives, combination vaginal ring, and the progestin contraceptive implant. The combination methods have forms of estradiol and progesterone to stop a woman from ovulating. The progestin-only methods typically affect the cervical and uterine environment so that pregnancy is avoided. In all cases, sex hormones are introduced, which play many different roles in our body and ultimately lead to skin changes in some women. If you browse skin care forums online, you will see many women who recommend trying a progestin-only form of contraception for alleviating melasma; however, there is no proof that this helps to treat the condition. In fact, Resnik reduced the estrogen component of the oral contraceptive to see whether it could alleviate melasma signs, but it had no effect.8 Even so, the only way to alleviate contraceptive-induced melasma is to stop taking the medication. While pregnancy-induced melasma will usually fade within a year after delivery, contraceptive-induced melasma will persist as long as the medication is used. In some cases, this can take years to fully resolve. In addition to the sex hormones, thyroid hormones may also play a role in melasma development. People with melasma are four times as likely to have a thyroid abnormality than those with normal skin pigmentation.1 While a number of hormones are involved in triggering melasma, their elevated levels are not always found in melasma skin, meaning they are not the ultimate factor in developing the disease.

A Vascular Disorder

Regardless of gender, melasma can appear on sun-exposed areas of the face as a flat, distinct area of discoloration. These dark patches typically appear on the forehead, cheeks and chin in a symmetrical fashion.1 Interestingly, vascular diseases like rosacea can also appear on these facial regions. Looking at the role that blood vessels play in the development of melasma in both men and women, scientists have found that melasma skin has a bigger quantity of large blood vessels than non-melasma skin.1,10 Not surprisingly, the vascular disease rosacea is also a common affliction among women. Eventually, new research will emerge that will look at the specific role that hormones play in vascular and pigmentary changes in order to grasp a better understanding of this frustrating condition.

The Three Ps

When it comes to treating a client with melasma, it is important to adhere to the three Ps for maximum results – patience, persistence and precaution. You and your client will need patience in getting results and you will need to manage your client's expectations. Since melasma is persistent, it will take regular visits to a skin care center along with daily care to manage and resolve this condition. Remember that hormones continuously trigger the condition so treatment of hormone-induced melasma should only begin after the client has finished breastfeeding or changed their contraceptive medication. Finally, precaution is crucial because you could inadvertently worsen the melasma pigmentation by triggering inflammation in the skin. Chemical peels can improve the appearance of epidermal melasma skin, but utmost care is needed when choosing the correct peel formulation and treatment protocol to avoid hyperpigmentation. Clients who tend to get melasma are also more sensitive to UV and harsh chemicals which can trigger hyperpigmentation; recommending the correct daily care products is very important for treatment outcome. Even though clients come in regularly for treatment, their skin may be different each time they visit. Pay special attention to your client's stress level as the stress hormone cortisol can sensitize skin and trigger inflammation. Since melasma pigmentation can worsen if the client is stressed, you may want to tackle the inflammation before the pigmentation.

Melasma, being a highly visible disorder, causes significant distress. With an arsenal of topical skin-lightening ingredients, laser technologies and education, skin care professionals can have a powerful effect not only on the skin's appearance, but also on the client's life and overall happiness.

References:

1. Sheth, V. M., & Pandya, A. G. (2011). Melasma: a comprehensive update: Part I. Journal of the American Academy of Dermatology, 65(4), 689-697.
2. Jablonski, N. G., & Chaplin, G. (2012). Human skin pigmentation, migration and disease susceptibility. Philosophical Transactions of the Royal Society B: Biological Sciences, 367(1590), 785-792.
3. Costin, G. E., & Hearing, V. J. (2007). Human skin pigmentation: melanocytes modulate skin color in response to stress. The FASEB Journal, 21(4), 976-994.
4. Paek, S. Y., & Pandya, A. G. (2013). Disorders of Hyperpigmentation. In Skin of Color (pp. 139-160). Springer New York.
5. Ortonne, J. P., et al. (2009). A global survey of the role of ultraviolet radiation and hormonal influences in the development of melasma. Journal of the European Academy of Dermatology and Venereology, 23(11), 1254-1262.
6. Kang, H. Y., & Ortonne, J. P. (2010). What should be considered in treatment of melasma. Annals of Dermatology, 22(4), 373-378.
7. Victor, F. C., Gelber, J., & Rao, B. (2004). Melasma: a review. Journal of Cutaneous Medicine and Surgery: Incorporating Medical and Surgical Dermatology, 8(2), 97-102.
8. Resnik, S. (1967). Melasma induced by oral contraceptive drugs. JAMA: the journal of the American Medical Association, 199(9), 601-605.
9. Jang, Y. H., et al. (2010). Oestrogen and progesterone receptor expression in melasma: an immunohistochemical analysis. Journal of the European Academy of Dermatology and Venereology, 24(11), 1312-1316.
10. Jang, Y. H., et al. (2012). The histopathological characteristics of male melasma: Comparison with female melasma and lentigo. Journal of the American Academy of Dermatology, 66(4), 642-649.

Dr. Claudia Aguirre is a neuroscientist working as the scientific communications manager for The International Dermal Institute (IDI) and Dermalogica. Aguirre applies the latest skin-relevant science and technology to the development of curriculum and digital media for IDI and Dermalogica worldwide. She received her Bachelor of Science Degree from the University of California, Los Angeles (UCLA) and earned her doctorate degree from the University of Southern California (USC), where she specialized in cellular and molecular neuroscience. She has received numerous awards, scholarships and fellowships during her studies and has been published in international scientific journals. Aguirre is also a frequent editorial contributor to publications worldwide.