Melasma
What is Melasma?
Melasma is an acquired hypermelanosis disorder characterized by symmetrically distributed hyperpigmented patches on the face. It is more common in women than men, and it usually affects sun-exposed areas including the face, neck, chest, forearms, and hands. The exact cause of melasma is unknown, but potential triggers include:
- Sun exposure
- Genetic predisposition
- Hormonal influences
- Women's endocrine changes associated with pregnancy, oral contraceptives, hormone replacement therapy, etc.
- Skin sensitivity to cosmetics and other skin care products
- Certain medical conditions, such as thyroid disease and adrenal insufficiency
Hypomelanosis is a lighter form of melasma and is often caused by the same mechanisms as darker forms, however light exposure may be a contributing factor.
Signs and Symptoms
Melasma usually manifests as brown, gray, or tan flat patches on the skin, usually on the face, neck, chest, and forearms. These patches are typically symmetrical on both sides of the face and can be localized or widespread. Some people may also develop hypopigmented patches (lighter patches), but this is less common.
The condition can worsen with sun exposure, so it is important to wear sun protection such as a broad-spectrum sunscreen with an SPF of at least 30. Sun protection is also important to prevent melasma from recurring after treatment.
Diagnosis and Treatment
Diagnosis is usually made based on the clinical presentation. A biopsy may be performed to confirm the diagnosis. Treatment of melasma typically includes a combination of topical and oral medications, and sometimes lasers, chemical peels, or other procedures. The aim of treatment is to reduce the appearance of the pigmented patches. Topical treatments usually include bleaching agents, such as hydroquinone, and inhibitors of melanin production, such as tretinoin. Oral medications can include antibiotics, antimalarials, or hormone-controlling drugs. Chemical peels and lasers may be used to reduce the appearance of the pigmented patches, but these treatments are typically more expensive and may have more adverse effects.
Prevention
The best way to prevent melasma is to limit exposure to the sun and use sun protection. It is important to wear a broad-spectrum sunscreen with an SPF of at least 30, and to reapply it frequently, especially after swimming or sweating. It is also important to avoid irritating the skin, as this can worsen the pigmentation.