Melasma

Melasma appears as patchy shades of brown pigmentation on sun-exposed areas of the face. Melasma is more common in females and in darker skin types, and less common in fair or very dark skin. 

It may occur in any population, but it is more common in those of East Asian, Indian, Pakistani, Middle Eastern and Mediterranean-African, Hispanic-American and Brazillian origin.

Proper treatment of the underlying medical condition is paramount, but excess hair removal can generally be provided concurrently with medical treatments. In addition, excessive hair growth can be genetic in nature. Though excessive hair growth due to genetic condition is not medically concerning, it may pose a major cosmetic concern.

What causes it?

Genetics: Some people are predisposed to this condition.

Hormones: Oestrogen from the pill or pregnancy stimulates the pigment producing cells in the skin, resulting in excess pigmentation. Some  people, despite having no history of pregnancy or being on the pill have melanocytes which are just sensitive to normal amounts of hormones.

UV Light Exposure: Even brief exposure to UV light can stimulate pigmentation.The regular use of sunscreen is a cornerstone of treating melasma.

How do patients present?

Patients usually give a history of the gradual onset of areas of dark facial skin. The pigmentation usually occurs on the face and is usually bilateral. The colour may vary from tan to brown, but it may be black or even have a blueish tinge. The distribution is usually symmetrical and three patterns are commonly seen – centrofacial, malar or mandibular.

The excess of melanin may be located in the superficial layers of the skin (epidermal melasma), the deeper layers of the skin (dermal melasma) but, more commonly, it is found in both layers of the skin (mixed melasma). The areas of skin most commonly affected are the forehead, cheeks and upper lip.

How is it diagnosed?

Melasma is usually diagnosed after examining the colour and pattern of the pigment. A Woods light (a special light used to assess the skin) may be used to determine the location of the pigment in those with lighter skin.

How is it treated?

Melasma is challenging to treat, but it can be treated with a combination of various regimes – lasers, chemical peels and topical and systemic medications.

• If hormonal factors appear to be causative, the use of the oral contraceptive pill should be discontinued.
• Strict sun protection is essential. A broad-spectrum sunscreen (SPF50+) with a high percentage of zinc oxide should be applied at least twice a day, twenty minutes prior to sun exposure. Broad-brimmed hats should also be worn when outdoors.
• Cosmetic camouflage like colour-matched make-up may conceal the majority of melasma but this would be limited where thepigmentation is too dark to be successfully covered up.
• Topical creams like Hydroquinone lotion (2 – 8%) in either a stand-alone formulation or mixed with other active ingredients is the most widely used method to treat melasma. It inhibits conversion of dopa to melanin and is applied to the affected areas at night for two to four months. It is more effective in combination with other agents, namely Tretinoin and mild steroid cream. Creams and lasers are often used in combination to treat this condition. The aim is initially to treat the redness first and then target the pigmented areas.
• Azelaic acid (20%) may improve cases of superficial melasma. It can be applied twice daily and may be used long term. 
• Systemic medications like transexamic acid can be used orally. The oral form is now used by many dermatologists, but is not    suitable for all patients.
• Laser and light-based treatment should only be used in cases where the aforementioned therapies appear to be refractive. Multiple treatments with laser are usually necessary to see a noticeable improvement. It is important that certain lasers should be used and these should be used with extreme care, under the guidance of a specialist laser dermatologist. Picosecond lasers (Picoway) is currently the most promising laser treatment of melasma (several treatments are required over many months to see improvements). Vascular laser treatment may be used to treat melasma if it has a red component.

What is the prognosis for melasma?

Epidermal melasma has a much better prognosis than mixed or dermal melasma, but all types are recurrent and require ongoing maintenance therapy. Melasma associated with pregnancy has the best chance of improvement, with pigment gradually fading over months. However, melasma often recurs in subsequent pregnancies.