Melasma: Causes, Diagnosis, Treatment & Prevention

• Melasma is a chronic pigmentation disorder that causes brown or gray-brown patches on the face and upper body
• Sun exposure and fluctuating hormones are two of its most common triggers
• Effective treatments include topical remedies, chemical peels, dermabrasion and laser therapy

Melasma is characterized by irregularly shaped patches on the face, neck, chest and forearms, and predominantly affects women and individuals with darker skin tones. This is a harmless skin condition that may resolve on its own depending on the cause, but sometimes requires treatment. In other cases, these patches may be permanent. 

This condition is considered difficult to treat. That being said, alongside preventive strategies, there are treatments that can successfully minimize the appearance of dark patches. Options include topical agents, chemical peels, dermabrasion and laser therapy. Preventive methods such as avoiding sunlight and wearing sunscreen can help mitigate flare-ups.

What Is Melasma?

Melasma is a type of pigmentary skin condition that causes dark and discolored patches to appear on the skin. There are three different types, each categorized by the depth of discoloration:

• Epidermal melasma: affects the epidermis (the outermost layer of the skin) 
• Dermal melasma: affects the dermis (the middle layer of the skin) 
• Mixed melasma: occurs in both the epidermis and dermis 

Melasma occurs when pigment-producing skin cells, known as melanocytes, produce too much pigmentation (melanin) in response to certain triggers: Two of the most common triggers are exposure to sunlight and fluctuating female sex hormones. 

As a result, it commonly presents on the most sun-exposed areas of the body and is more prevalent in women. 

Those with darker skin tones are also more likely to develop this condition as they have more melanocytes in their skin. Other contributing factors include having a family history of melasma and stress. 

Effective treatment hinges on the particular trigger – symptoms may appear intermittently depending on sun exposure or if certain drugs such as birth control pills are discontinued.

Melasma Symptoms

Those with melasma will notice irregularly shaped patches of discoloration on their skin. These patches are considerably darker than the surrounding skin color, and are brown, gray-brown or grayish in color. They can also vary in intensity depending on the depth of the pigmentation.  

As one of the main triggers is sunlight, it tends to occur on the face, specifically the cheeks, forehead, nose, chin and above the upper lip. 

Although uncommon, it may also develop on other sun-exposed areas of skin such as the neck, chest, upper back and forearms. The presence of melasma in these areas is more prevalent in women experiencing menopause – commonly associated with fluctuating hormone levels. 

How is melasma diagnosed?

A dermatologist will examine your skin to determine if you have melasma. In most cases, it will be analyzed beneath a Wood’s light to determine severity. A Wood’s light is a small device used by dermatologists to examine skin pigmentation. It utilizes long-wave ultraviolet light (UV-A) to illuminate and reveal affected areas of the skin. 

Beyond examination with a Wood’s light, a skin biopsy may also be required in order to rule out more serious skin conditions. 

Similar conditions

Melasma can sometimes be confused with other conditions that have similar symptoms. Most notably, this includes postinflammatory hyperpigmentation (PIH) and drug-induced hyperpigmentation. 

PIH is a by-product of inflammation or trauma to the skin. It can develop as a result of acne, eczema or an allergic reaction, and causes dark patches of skin at the point of injury. 

Exposure to certain drugs or medications can also cause areas of dark pigmentation. This is called drug-induced hyperpigmentation, and can easily be mistaken for melasma. Many classes of drugs have been identified including antibiotics, nonsteroidal anti-inflammatory drugs (NSAIDS) and psychotropic drugs.

What Causes Melasma?

Hormonal fluctuations and sun exposure are the main causes of melasma – but there are several other triggers that can cause it to develop or worsen over time. 

Hormonal triggers

Fluctuating hormones, specifically the female reproductive hormones estrogen and progesterone, are one of the main causes of melasma. Pregnant women in particular often develop it, which is why it is commonly referred to as the pregnancy mask or mask of pregnancy.  

Other potential hormonal triggers include:

• Hormone replacement therapy (HRT)
• Menopause
• Oral contraceptives (birth control pills)
• Thyroid and ovarian disorders

Sun exposure

Ultraviolet (UV) light stimulates melanocyte production in the skin, which causes dark patches or darkens existing patches. While this exposure typically comes from the sun’s rays, tanning beds are also responsible.  

Medications

While drug-induced hyperpigmentation is caused by specific classes of drugs, melasma is associated with other drugs including steroids, photosensitizing agents, and cosmetics that contain certain chemicals. These can all cause a reaction in the skin, resulting in increased pigmentation. 

Other melasma triggers

Beyond fluctuating hormones and exposure to UV light, stress can induce a flare-up in people who have this condition. This is a result of the body increasing levels of the hormone cortisol as a means of coping with the stress. Cosmetics that contain certain chemicals are also known triggers.

Genetics have a strong influence on melasma development; science has determined that more than 40% of patients have a family history of the condition. 

Melasma Treatments

Treatments are aimed at controlling and reducing the appearance of melasma. Topical agents can effectively reduce the appearance of dark patches by inhibiting melanin production and boosting skin cell turnover. Chemical peels, dermabrasion and laser therapy target excess melanin buildup by physically removing dark areas of pigmentation.  

Topical treatments

Topical medications are typically first-line treatments to help lighten pigmented skin and do so by inhibiting melanin production. There are a great range of topics to choose from. 

Hydroquinone is a mainstay of melasma management as it is very effective in lightening skin by inhibiting pigment production. 

Retinoids such as tretinoin boost skin cell turnover to enable fresh new skin cells to take the place of pigmented cells. 

One strongly recommended treatment is a triple combination cream containing hydroquinone, tretinoin and corticosteroid. In addition to increasing cell turnover, the antibiotic reduces inflammation. 

Chemical peels

Chemical peels are second-line treatments in melasma management. They improve the appearance of skin by removing the outer layers of skin and stimulating skin cell production to reveal a fresh layer beneath.

Three types of chemical peels are available for treating pigmented areas of skin:

• Alpha hydroxy acid (AHA)
• Beta hydroxy acid (BHA)
• Trichloroacetic acid (TCA)

Multiple peeling sessions are usually required, and continued use of hydroquinone or combination cream between sessions can help prevent melanin buildup. 

Dermabrasion

Dermabrasion is a type of skin resurfacing procedure which utilizes a rapidly rotating device to remove the outermost layers of skin and stimulate skin cell growth.  

As with chemical peels, results are best when dermabrasion is used alongside hydroquinone or combination cream to inhibit melanin production. 

Laser treatments

Laser treatments are a third-line approach that is considered for those who fail to respond to topical or chemical peel treatments. It has the benefit of accelerating skin lightening but unlike hydroquinone, it does not treat the underlying cause of melasma. Several laser treatments are available and include:

• Intense pulsed light (IPL)
• Nonablative fractionated lasers
• Q-switched lasers
• Picosecond lasers

These lasers use both high- and low-intensity pulses of light with varying wavelengths to penetrate the skin and destroy pigment. This also recreates micro wounds which stimulate collagen production and resurfaces skin.

Minimizing the appearance of melasma

Makeup can conceal the appearance of dark patches of skin. Look for products such as tinted moisturizers, concealers, foundations and powders. Opt for moisturizers and foundations that have SPF built into them to provide an extra layer of protection from sun-damaging rays. 

Melasma Prevention

Preventative measures can go a long way to prevent melasma from worsening or recurring after treatment:

• Wear sunscreen with a sun protection factor (SPF) of at least 30
• Cover up when exposed to the sun and choose shady areas when possible.
• Avoid tanning beds 
• Choose gentle, unscented, noncomedogenic skin care products to avoid irritating skin and worsening this condition

Takeaway

Melasma is a skin disorder that has several possible triggers: sun exposure and hormonal fluctuation are the most common. 

Depending on the individual, melasma can resolve on its own, or it may successfully respond to treatment. In other cases, the pigmented skin is permanent. Fortunately, with effective sun protection and hormonal stabilization most cases of melasma will eventually fade away. 

Treatments are aimed at controlling and reducing the appearance of melasma. For those with chronic melasma, there are several effective options that work to limit the appearance of pigmented areas, either by blocking melanin production or physically removing dark pigmentation from the skin’s surface.