Melasma

Melasma is an acquired, chronic pigmentary disorder predominantly affecting women. 

 

 

Called chloasma, or the “mask of pregnancy,” when it occurs in pregnant women. 

 

 

90 percent of people who develop melasma are women.

May be idiopathic.

Acquired disorder of hypermelanosis characterized by symmetrically distributed hyperpigmented macules/patches involving sun exposed areas, primarily on the face.

Causes patches of discoloration. 

 

 

The patches are darker than the usual skin color. 

 

 

It typically occurs on the face and is symmetrical, with matching marks on both sides of the face. 

 

 

It presents as bilateral, brown macules or patches on the malar cheeks, forehead, upper lip, and/or mandible, most commonly in a centrofacial pattern.

Melasma is a common acquired condition of symmetric hyperpigmentation, typically occurring on the face, with higher prevalence in females and darker skin types.

Other areas of the body that are often exposed to sun can also develop melasma.

 

Brownish colored patch lesions usually appear on the:

cheeks

forehead

bridge of the nose

chin

neck

forearms. 

The skin discoloration is not associated with harm.

Darker-pigmented individuals are more at risk than those with fair skin. 

 

 

Histologically it  is characterized by increased melanin in the epidermis and/or dermis. 

While melasma can occur in both men and women, it is much more common in women of reproductive age and those of darker skin types (Fitzpatrick types III and IV).

Occurs during pregnancy in 25% of cases.

Prevalence of melasma in pregnant women ranges between approximately 15-20%.

Rarely seen prior to puberty.

Melasma can occur on the arms and chest, but the facial location is the most common location by far.

On the face, there are 3 major patterns of involvement including: 1) centrofacial, involving the cheeks, forehead, upper lip, nose, and chin, 2) malar, involving the cheeks and nose, 3) mandibular, involving the ramus of the mandible.

Most common in women of reproductive age, especially in their 30s-40s.

Affects all racial groups but is most prevalent in dark skinned individuals with Fitzpatrick skin types IV to VI, especially Hispanic/Latino, Asian, and African-American persons.

Prevalence 4-10% among Latina women.

Prevalence is as high as 40% in Southeast Asian women.

Male to female ratio is approximately 9 to 1.

Pathogenesis involves an interplay of various factors, the most important being chronic UV exposure.

Other risk factors include: genetic predisposition, thyroid dysfunction, pregnancy, use of scented cosmetics, oral contraceptive pills, hormonal therapy, photosensitizing agents, and medications to include phenytoin, imatinib, amiodarone, and tetracyclines.

Estrogen and progesterone hormone sensitivity  are also associated with the condition: birth control pills, pregnancy, and hormone therapy can all trigger melasma. 

 

 

Underlying stress and thyroid disease are thought to be causes of melasma.

 

 

Sun exposure can cause melasma, due to ultraviolet rays affecting  melanocytes

UV radiation stimulates melanogenesis by direct effects on melanocytes and indirectly effects keratinocytes releasing melalanogenic factors.

Poorly defined blotchy, tan macules and patches involving the cheeks, forehead and temples bilaterally.

Often resolves spontaneously with cessation of hormonal stimulus.

Can be exaggerated with sun exposure.

Related to the alterations in melanocytes with increased transfer of pigment to basal keratinocytes or to dermal macrophages.

About 90% of patients are female.

Lesions typically located around the forehead, temples, cheeks, and upper eyelids.

Lesions increase in size over time and become increasingly dark with sun exposure.

A Wood’s lamp examination aids  in diagnosis.

 

Diagnosis is clinical.

 

Its clinical course  is often protracted and resistant to treatment.

The process often returns after discontinuation of treatment or with increased sun exposure.

 

 

Treatments to hasten the fading of the discolored patches include:

Topical depigmenting agents, such as hydroquinone (HQ.

HQ is a chemical that inhibits tyrosinase, an enzyme involved in the production of melanin.

Tretinoin, is an acid that increases skin cell turnover. 

Azelaic acid is thought to decrease the activity of melanocytes.

Tranexamic acid provides rapid and sustained lightening in melasma by decreasing melanogenesis in epidermal melanocytes.

The most effective therapy  includes a combination of topical agents.

 

Cosmetic camouflage can also be used to hide melasma.

Topical therapies utilized include: depigmenting agents, retinoids, corticosteroids, visible and UV light protection, tranexamic acid (TXA), and combination creams. 

Chemical peels include glycolic acid, salicylic acid. and trichloroacetic acid (TCA). 

Laser- and light-based therapies include intense pulsed light, yttrium, pulsed-dye and fractionated laser.

Laser- and light-based devices have  mixed results. 

Intense pulsed light has been shown to improve melasma.

Topical hydroquinone is the most extensively studied treatment for melasma, and has demonstrated an excellent safety profile. 

Sometimes a medicine contains three medicines (hydroquinone, tretinoin, and a corticosteroid) in one cream. 

This triple cream (TCC) is be most effective treatment for melasma

TCC safety has been established in studies of daily use up to 12 months. 

Relapse rates are most closely tied to severity of melasma at baseline. 

The use of sunscreen with SPF ≥ 30 is mandatory in the management of melasma.

Depigmenting agents, such as topical TXA, have not shown higher efficacy when compared with HQ. 

Microneedling using TXA has shown promising results. 

Azelaic acid was found to be more effective than 2% HQ, but equivalent to 4% HQ cream, although it garnered more adverse effects. 

Vitamin C decreases skin pigmentation and is an alternative treatment when HQ is not an option. 

Topical tretinoin 0.05–0.1% has shown efficacy in most studies, however, longterm use is necessary for clinical improvement.

Chemical peels reviewed did not show consistent results. 

 

There are many negative side effects that go along with these treatments and many times treatments are unsatisfying overall: scarring, irritation, lighter patches of skin, and contact dermatitis are all commonly seen to occur.

Patients should avoid other precipitants including hormonal triggers.

Oral medications and dietary supplements employed in the treatment of melasma include tranexamic acid, Polypodium leucotomos extract, beta‐carotenoid, melatonin, and procyanidin.

In randomized, double-blind, placebo-controlled trial in 56 Filipino women, there was significant improvements in the left and right malar regions with procyanidin.

Treatments strip away the top layers of skin and may help lighten dark patches.

Minimizing sun exposure and wearing sunscreen daily, using makeup , wearing a wide-brimmed hat that shields or provides shade, and wearing protective clothing  measures are preventative.

 

 

Melasma disappears on its own, typically with pregnancy or birth control pills.

 

In all treatments, effects are gradual and avoidance of sunlight is  necessary.

The use of broad-spectrum sunscreens with physical blockers, such as titanium dioxide and zinc dioxide is preferred over that with only chemical blockers. 

This is because UV-A, UV-B and visible lights are all capable of stimulating pigment production.

 

 

Topical steroids to help lighten the affected areas, and chemical peels, dermabrasion, and microdermabrasion are possible options. 

 

Interventions include:  topical agents, chemical peels, laser- and light-based devices, and oral agents. 

 

 

Triple combination cream: hydroquinone, tretinoin, and corticosteroid, remains the most effective treatment, as well as hydroquinone alone. 

Topical hydroquinone 2-4% alone or in combination with other topical agents are commonly used treatments.

Addition of retinoic acid prevents oxidation of hydroquinone and improves its epidermal penetration and keratinocyte proliferation.

 

Chemical peels and laser- and light-based devices have mixed results. 

 

PDL laser is the only treatment that has shown decrease in the relapse of melasma, mainly targeting the vascular component of melasma. 

Laserand light-based devices should be considered as a third-line treatment for melasma, and should be used judiciously in dark-skinned subjects.

No topical, oral, or light-based monotherapy treatment guarantees improvement of melasma. 

 

Oral tranexamic acid is a promising treatment for moderate and severe recurrent melasma. 

 

 

Hydroquinone monotherapy and triple combination cream are the most effective and well-studied treatments for melasma, whereas chemical peels and laser- and light-based therapies are equal or inferior to topicals, but offer a higher risk of adverse effects.