Melasma (also known as chloasma faciei or the mask of pregnancy when it occurs in pregnant women) is a common skin disorder characterized by tan, brown, or grayish hyperpigmented patches, usually on the face.
The exact cause of melasma is not fully understood, but it is believed to result from a combination of factors including ultraviolet (UV) radiation exposure, hormonal influences (such as pregnancy or the use of oral contraceptives and hormone replacement therapy), genetics, and skin irritation.
Although melasma can affect anyone, it occurs more frequently in women, particularly those with darker skin types and those living in areas of intense sun exposure. It is considered a chronic and relapsing condition that may require ongoing management.
Signs and symptoms
The symptoms of melasma are dark, irregular, well-demarcated, hyperpigmented macules to patches. These patches often develop gradually over time. Melasma does not cause any other symptoms beyond the cosmetic discoloration.
Cause
The exact cause of melasma is unknown. It is thought that the overproduction of melanocyte-stimulating hormone brought on by stress can cause outbreaks of this condition. Other rare causes of melasma include allergic reaction to medications and cosmetics.
Addison's disease
Melasma suprarenale (Latin: 'above the kidneys') is a symptom of Addison's disease, particularly when caused by pressure or minor injury to the skin, as discovered by FJJ Schmidt of Rotterdam in 1859.
Diagnosis
Types
The two different kinds of melasma are epidermal and dermal.
- Epidermal melasma results from melanin pigment that is elevated in the suprabasal layers of the epidermis.
- Dermal melasma occurs when the dermal macrophages have an elevated melanin level. Melasma is usually diagnosed visually or with assistance of a Wood's lamp (340–400 nm wavelength). Under Wood's lamp, excess melanin in the epidermis can be distinguished from that of the dermis. This is done by looking at how dark the melasma appears; dermal melasma appears darker than epidermal melasma under the Wood's lamp. HQ inhibits tyrosinase, an enzyme involved in the production of melanin.
- Tretinoin, a retinoid, increases skin cell (keratinocyte) turnover. This treatment is not used during pregnancy due to risk of harm to the fetus.
- Azelaic acid (20%) is thought to decrease the activity of melanocytes.
- Tranexamic acid by mouth has shown to provide rapid and sustained lightening in melasma by decreasing melanogenesis in epidermal melanocytes.
- Cysteamine hydrochloride (5%) over-the-counter Mechanism of action seems to involve inhibition of melanin synthesis pathway
- Kojic acid (2%) OTC
- Chemical peels
- Microdermabrasion to dermabrasion (light to deep)
Effectiveness
Evidence-based reviews found that the most effective therapy for melasma includes a combination of topical agents. More recently, a systematic review found that oral medications also have a role in melasma treatment, and have been shown to be efficacious with a minimal number and severity of adverse events. Oral medications and dietary supplements employed in the treatment of melasma include tranexamic acid, Polypodium leucotomos extract, beta‐carotenoid, melatonin, and procyanidin.
Oral procyanidin combined with vitamins A, C, and E shows promise as safe and effective for epidermal melasma. In an 8-week randomized, double-blind, placebo-controlled trial in 56 Filipino women, treatment was associated with significant improvements in the left and right malar regions, and was safe and well tolerated. In all of these treatments, the effects are gradual and a strict avoidance of sunlight is required. The use of broad-spectrum sunscreens with physical blockers, such as titanium dioxide and zinc oxide, is preferred, because UV-A, UV-B, and visible lights are all capable of stimulating pigment production. Many negative side effects can go along with these treatments, and treatments often are unsatisfying overall. Scarring, irritation, lighter patches of skin, and contact dermatitis are all commonly seen.