Melasma

Malasma is known as the mask of pregnancy. Melas, in Greek language, means black. It is defined as asquired increase in pigmentation of sun exposed skin. The cheeks, the upper lip, the chin, and the forehead are the most common location, but it can occasionally occur in other sun-exposed location as well.

Dr. Najjia Ashraf


In many cases, a direct relationship with female hormonal activity appears to be present because it occurs with pregnancy and with the use of oral contraceptive pills. Other factors that might be responsible are photosensitising medications, mild ovarian or thyroid dysfunction, and certain cosmetics. The most important factor in the development of melasma is exposure to sunlight. Without the strict avoidance of sunlight, potentially successful treatments for melasma are doomed to fail.

Persons of any race can be affected. However, it is much more common in constitutionally darker skin types than in lighter skin types, and it may be more common in light brown skin types, especially Hispanics and Asians, from areas of the worlMelasma is much more common in women than in men. Women are affected in 90% of cases. When men are affected, the clinical picture is identical.

Melasma is rare before puberty and most commonly occurs in women during their reproductive years.
n Patients may inquire about progressive increase of pigmentation of the face, which may be temporarily related to pregnancy or to the use of oral contraceptive pills.

Intense or chronic exposure to sunlight worsens the condition and may precipitate melasma, but because the development of pigmentation is often insidious, patients may not recognise the association.

n The increased pigmentation of melasma is commonly tan to brown. Blue or black may be evident in patients with dermal melasma. The distribution is one of three patterns: centre of face, over cheeks, or over jaw line. A rare pattern confined to the forearms is seen in women receiving exogenous progesterone.

n The excess melanin can be visually localized to the epidermis (superficial layer of skin) or the dermis (deep layer of skin) by use of a Wood lamp (wavelength, 340-400 nm). d with intense sun exposure.

Melasma is much more common in women than in men. Women are affected in 90% of cases. When men are affected, the clinical picture is identical.

Melasma is rare before puberty and most commonly occurs in women during their reproductive years.
n Patients may inquire about progressive increase of pigmentation of the face, which may be temporarily related to pregnancy or to the use of oral contraceptive pills.

Intense or chronic exposure to sunlight worsens the condition and may precipitate melasma, but because the development of pigmentation is often insidious, patients may not recognise the association.

n The increased pigmentation of melasma is commonly tan to brown. Blue or black may be evident in patients with dermal melasma. The distribution is one of three patterns: centre of face, over cheeks, or over jaw line. A rare pattern confined to the forearms is seen in women receiving exogenous progesterone.

n The excess melanin can be visually localized to the epidermis (superficial layer of skin) or the dermis (deep layer of skin) by use of a Wood lamp (wavelength, 340-400 nm).

A genetic predisposition is a major factor in the development of melasma. It is much more common in women than in men. Persons with light brown skin types from regions of the world with intense sun exposure are much more prone to the development of melasma. More than 30% of patients have a family history of melasma.

Another major factor is exposure to sunlight. Ultraviolet radiation can lead to generation of free radicals, which could stimulate melanocytes to produce excess melanin. Sun-screens that primarily block UV-B radiation (290-320 nm) are unsatisfactory because longer wavelengths (UV-A and visible radiation, 320-700 nm) also stimulate melanocytes to produce melanin.
The exact mechanism by which pregnancy affects melasma is unknown. Estrogen, progesterone, and melanocyte-stimulating hormone (MSH) levels are normally increased during the third trimester of pregnancy.

Care and treatment

Melasma can be difficult to treat. The pigment of melasma develops gradually, and resolution is also gradual. Resistant cases or recurrences occur often and are certain if strict avoidance of sunlight is not rigidly heeded. All wavelengths of sunlight, including the visible spectrum, are capable of inducing melasma.

In an attempt to hasten resolution, many practitioners attempt mild exfoliation with superficial chemical peels.
The mainstay of treatment remains topical depigmenting agents. Hydroquinone (HQ) is most commonly used.
n Efficacy is directly linked to concentration, but the incidence of adverse effects also increases with concentration. All concentrations can lead to skin irritation, phototoxic reactions with secondary post-inflammatory hyperpigmentation, and irreversible increase in pigmentation (reported even with long-term use of 2% HQ).

n The use of tretinoin (trans-retinoic-acid) can be effective as monotherapy. However, the response to treatment is less than with HQ and can be slow, with improvement taking six months or longer. The major adverse effect is skin irritation, especially when the more effective, higher concentrations are used. Temporary photosensitivity and paradoxical hyperpigmentation can also occur.

n Azelaic acid, available as a 20% cream-based formulation, appears to be as effective as 4% HQ and superior to 2% HQ in the treatment of melasma. The primary adverse effect is skin irritation. No phototoxic or photoallergic reactions have been reported.
n Mild superficial chemical peels.

Patient Education

n Strict sun avoidance is essential for resolution and to prevent recurrence.
n Patients should apply bleaching creams to areas of darkening only.
n Resolution with strict sun avoidance and topical bleaching creams can take months; caution patients to expect slow but gradual lightening.