Melasma

What is it?

Melasma is a common acquired pigmentary disorder characterized by symmetrical brown to grayish-brown patches on sun-exposed areas of the face. The condition results from excessive melanin (skin pigment) production in the epidermis and dermis, creating areas of hyperpigmentation (darkening) that are often resistant to treatment and prone to recurrence. Sometimes referred to as "chloasma" or the "mask of pregnancy" when occurring during gestation, melasma represents a chronic condition requiring long-term management.

Who is affected?

Melasma affects approximately 1% of the general population, with prevalence reaching 9-50% in higher-risk groups.

• Prevalence: Affects 1 in 100 people (1%) in the general population; significantly higher in women of reproductive age and individuals with darker skin types
• Age demographics: Peak onset between ages 20-40 years; rarely occurs before puberty
• Gender distribution: Predominantly affects women (90% of cases); men represent approximately 10% of patients
• Risk factors: Darker skin phototypes (Fitzpatrick types III-V); pregnancy (15-50% of pregnant women); hormonal contraceptives and hormone replacement therapy; family history (up to 50% report affected relatives); ultraviolet and visible light exposure; certain medications (phototoxic drugs)

What causes it?

Melasma results from complex interactions between genetic, hormonal, and environmental factors:

• Ultraviolet radiation: UV exposure activates melanocytes (pigment-producing cells) and upregulates melanin synthesis through multiple pathways including p53 activation
• Visible light exposure: Blue light (400-500 nm wavelength) triggers melanogenesis through Opsin-3 photoreceptors, particularly in darker skin types
• Hormonal influences: Estrogen and progesterone stimulate melanocyte activity; pregnancy, oral contraceptives, and hormone therapy are common triggers
• Genetic predisposition: Family history present in 40-50% of patients, suggesting hereditary susceptibility
• Dermal changes: Increased vascularization, mast cell infiltration, and solar elastosis (sun damage) in affected skin contribute to the disorder
• Oxidative stress: Free radical damage and inflammatory mediators play a role in pathogenesis

What are the clinical features?

Melasma presents as well-demarcated, irregularly shaped patches of hyperpigmentation on the face.

Distribution patterns:

• Centrofacial pattern (most common, 50-80%): Forehead, cheeks, upper lip, nose, and chin
• Malar pattern: Predominantly on the cheeks and nose
• Mandibular pattern: Along the jawline and chin

Clinical characteristics:

• Symmetric, bilateral distribution
• Color ranges from light brown to dark brown or grayish-blue
• Patches have irregular but well-defined borders
• No associated scaling, inflammation, or symptoms
• Worsening during summer months and improvement in winter

Depth classification (assessed by Wood lamp examination):

• Epidermal melasma: Well-defined borders under Wood lamp; responds better to treatment
• Dermal melasma: Less defined borders; more resistant to therapy
• Mixed melasma: Combination of epidermal and dermal involvement (most common)

How is it diagnosed?

Diagnosis is primarily clinical, based on characteristic appearance and distribution:

• Clinical examination: Recognition of symmetric hyperpigmented patches in typical facial locations; assessment of pattern and extent
• Wood lamp examination: Ultraviolet light helps determine pigment depth (epidermal, dermal, or mixed); enhances visualization of affected areas
• Dermoscopy: Reveals brownish pigmentation with pseudoreticular pattern; vascular component may be visible
• Skin biopsy: Rarely needed; may be performed to exclude other pigmentary disorders; shows increased melanin in epidermis and/or dermis
• Differential diagnosis: Must distinguish from post-inflammatory hyperpigmentation, solar lentigines, drug-induced pigmentation, and other facial melanoses

What treatment options are available?

Treatment aims to reduce melanin production, promote existing pigment turnover, and prevent recurrence:

Topical therapies (first-line):

• Triple combination cream (hydroquinone 4% + tretinoin 0.05% + fluocinolone 0.01%): Most effective topical treatment
• Hydroquinone 2-4%: Melanin synthesis inhibitor; gold standard depigmenting agent
• Tretinoin: Enhances epidermal turnover and hydroquinone penetration
• Azelaic acid 15-20%: Alternative for those intolerant to hydroquinone
• Vitamin C, kojic acid, arbutin: Adjunctive agents with modest efficacy

Oral therapies:

• Tranexamic acid 250 mg twice daily: Emerging treatment with good efficacy and safety profile
• Oral antioxidants (Polypodium leucotomos extract): Adjunctive photoprotection

Procedural interventions:

• Chemical peels (glycolic acid, salicylic acid): Enhance topical penetration and accelerate pigment removal
• Microneedling: Improves topical agent delivery
• Laser therapy: Q-switched lasers or fractional resurfacing; risk of post-inflammatory hyperpigmentation

Essential adjunctive measures:

• Broad-spectrum sunscreen (SPF 50+) with iron oxide for visible light protection
• Wide-brimmed hats and sun avoidance
• Discontinuation of hormonal triggers when possible

Prognosis:

• Chronic, relapsing condition requiring maintenance therapy
• Response to treatment varies; complete clearance is often not achievable
• Recurrence is common, especially with sun exposure or hormonal changes
• Long-term sun protection is essential for sustained improvement

Key points for patients

• Melasma is a cosmetic concern that poses no health risk but can significantly impact quality of life
• Sun protection is the cornerstone of treatment and prevention—even brief sun exposure can trigger recurrence
• Treatment requires patience; visible improvement typically takes 2-4 months
• When to seek medical attention: New or changing pigmentation, irregular borders or multiple colors (to exclude other conditions)
• Prevention strategies: Daily broad-spectrum sunscreen (reapplied every 2 hours during sun exposure); protective clothing; avoid peak sun hours; consider iron oxide-containing sunscreens to block visible light
• Hormonal factors should be discussed with your physician if considering contraception or hormone therapy