Melasma facts

Melasma facts

Melasma is most common in women 20-50 years of age.

Melasma looks like brown, tan, or blue-gray spots on the face (hyperpigmentation).

Melasma is characterized by three location patterns (central face, cheekbone, and jawline).

Melasma is caused partly by sun, genetic predisposition, and hormonal changes.

The most common treatment is topical creams containing hydroquinone.

Melasma prevention requires sun avoidance and sun protection with hats and sunscreen.

What is melasma? What are signs of melasma?

Melasma is a very common patchy brown, tan, or blue-gray facial skin discoloration, 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. Although possible, it is uncommon in males. Most of those with melasma are women. It is thought to be 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 an underlying factor. Melasma is most common among pregnant women, especially those of Latin and Asian descents. People with olive or darker skin, like Hispanic, Asian, and Middle Eastern individuals, have higher incidences of melasma.

Prevention is primarily aimed at facial sun protection and sun avoidance. Treatment requires regular sunscreen application, medications such as 4% hydroquinone and other fading creams.

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 progesterone), family history of melasma, race, antiseizure medications, and other medications that make the skin more prone to pigmentation after exposure to ultraviolet (UV) light. Uncontrolled sunlight exposure is considered the leading cause of melasma, especially in individuals with a genetic predisposition to this condition. Clinical studies have shown that individuals typically develop melasma in the summer months, when the sun is most intense. In the winter, the hyperpigmentation in melasma tends to be less visible or lighter.

When melasma occurs during pregnancy, it is also called chloasma, or "the mask of pregnancy." Pregnant women experience increased estrogen, 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 estrogen and MSH. Studies have shown that postmenopausal women who receive progesterone hormone replacement therapy are more likely to develop melasma. Postmenopausal women receiving estrogen alone seem less 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 stimulating pigment production. These individuals may also consider discussing their concerns with their doctor and avoiding birth control pills and hormone replacement therapy (HRT) if possible.

Where is melasma seen on the body?

Melasma is characterized by discoloration or hyperpigmentation primarily on the face. Three types of common facial patterns have been identified in melasma, including centrofacial (center of the face), malar (cheekbones), and mandibular (jawbone).

The centrofacial pattern is the most prevalent form of melasma and includes the forehead, cheeks, upper lip, nose, and chin. The malar pattern includes the upper cheeks. The mandibular pattern is specific to the jaw.

The upper sides of the neck may less commonly be involved in melasma. Rarely, melasma may occur on other body parts like the forearms. One study confirmed the occurrence of melasma on the forearms of people being given progesterone. This was a unique pattern seen in a Native American study.

What are the types of melasma?

Four types of pigmentation patterns are diagnosed in melasma: epidermal, dermal, mixed, and an unnamed type found in dark-complexioned individuals. The epidermal type is identified by the presence of excess melanin in the superficial layers of skin. Dermal melasma is distinguished by the presence of melanophages (cells that ingest melanin) throughout the dermis. The mixed type includes both the epidermal and dermal type. In the fourth type, excess melanocytes are present in the skin of dark-skinned individuals.

How is melasma diagnosed?

Melasma is readily diagnosed by recognizing the typical appearance of brown skin patches on the face. Dermatologists are physicians who specialize in skin disorders and often diagnose melasma by visually examining the skin. A black light or Wood's light (340-400 nm) can assist in diagnosing melasma, although is not essential for diagnosis. In most cases, mixed melasma is diagnosed, which means the discoloration is due to pigment in the dermis and epidermis. Rarely, a skin biopsy may be necessary to help exclude other causes of this local skin hyperpigmentation.