Melasma: Causes, Treatments, and What Actually Works

What Is Melasma and Who Gets It?

Melasma is a chronic acquired hyperpigmentation disorder that presents as symmetric brown or grey-brown patches on the face. It is not dangerous, but it carries a significant quality-of-life burden. The condition affects an estimated 1% of the general population worldwide and up to 50% of pregnant women in certain ethnic groups [1].

Three clinical patterns define the condition: centrofacial (cheeks, forehead, upper lip, nose, and chin), malar (cheeks and nose only), and mandibular (jawline). The centrofacial pattern accounts for roughly 65% of cases [2]. A Wood lamp examination helps classify the pigment depth. Epidermal melasma appears darker under Wood lamp and responds better to topical therapy. Dermal melasma shows little enhancement and is harder to treat. Most patients have a mixed pattern.

Women of reproductive age with Fitzpatrick skin types III through V carry the highest risk. A genetic component is well-documented. One cross-sectional study of 324 melasma patients found that 48% reported a first-degree relative with the same condition [3]. Men represent roughly 10% of cases, and male melasma tends to present with the same distribution patterns and responds to the same treatments [2].

The pathophysiology extends beyond simple melanocyte overactivity. Melasma skin shows increased vascularization, basement membrane disruption, solar elastosis, and mast cell infiltration compared to adjacent unaffected skin [4]. This means melasma is not purely a pigment problem. It is a complex photoaging phenotype, which explains why single-agent therapies often fall short.

What Triggers Melasma?

Ultraviolet radiation is the single most consistent trigger, and even brief unprotected sun exposure can reactivate treated melasma within days. Both UVA and UVB stimulate melanogenesis, but visible light (400 to 700 nm wavelength) also contributes, especially in darker skin types [5].

Hormonal factors rank second. Pregnancy triggers melasma in 15% to 50% of pregnant women, earning the condition its historical name "chloasma" or "mask of pregnancy" [1]. Combined oral contraceptives and estrogen-containing hormone replacement therapy are well-established triggers. The mechanism involves estrogen receptor upregulation on melanocytes, increasing their sensitivity to UV-induced pigment production [6].

Other documented triggers include thyroid autoimmunity, phototoxic medications, and cosmetics containing fragranced ingredients. Heat alone, independent of UV, can worsen melasma. One controlled study showed that infrared radiation and increased skin temperature stimulate melanogenesis through separate pathways from UV [5]. This is why patients who cook over open flames or use saunas may notice flares.

Stress also plays a role through cortisol-mediated pathways. Cortisol increases melanocyte-stimulating hormone (MSH) receptor expression, which can amplify pigmentation in predisposed individuals [7]. The condition is not "just cosmetic." The Melasma Quality of Life Scale (MELASQoL) consistently shows emotional distress scores comparable to other chronic dermatologic conditions like psoriasis [8].

First-Line Treatment: Triple Combination Cream

The modified Kligman formula (hydroquinone 4%, tretinoin 0.05%, fluocinolone acetonide 0.01%) is the most studied and effective topical treatment for melasma. A key 8-week randomized controlled trial of 641 patients showed that triple combination cream achieved complete or near-complete clearing in 26.1% of patients vs. 4.6% for hydroquinone alone [9].

Hydroquinone works by inhibiting tyrosinase, the rate-limiting enzyme in melanin synthesis. Tretinoin accelerates epidermal turnover and enhances hydroquinone penetration. The low-potency corticosteroid reduces irritation from the other two agents and has a mild depigmenting effect of its own [9]. The three ingredients together produce results that none achieves individually.

Standard protocol: apply a thin layer to affected areas once nightly for 8 to 12 weeks. The American Academy of Dermatology (AAD) recommends reassessment at 8 weeks [10]. If improvement is adequate, many clinicians taper to two or three nights per week as maintenance. Continuous daily use beyond 12 weeks raises the theoretical risk of exogenous ochronosis, though this complication is rare with 4% formulations under medical supervision.

Patients should expect visible lightening by week 4 to 6. Full response takes 8 to 12 weeks. Those who see no improvement by 12 weeks likely have significant dermal pigment and may need alternative or adjunctive therapies [10].

Oral Tranexamic Acid: The Evidence

Tranexamic acid (TXA), a synthetic lysine analog originally developed as an antifibrinolytic, has become the most significant addition to the melasma treatment toolkit in the past decade. It works by blocking plasminogen activator on keratinocytes, which interrupts the UV-induced melanogenic pathway and reduces vascular proliferation in melasma lesions [11].

The largest randomized controlled trial to date enrolled 561 melasma patients across centers in Singapore and compared oral TXA 250 mg twice daily against placebo for 24 weeks. The TXA group showed a mean MASI score reduction of 3.10 points greater than placebo (P<0.001), with 49.0% of TXA patients achieving a clinically meaningful improvement vs. 26.3% on placebo [12]. A 2020 systematic review and meta-analysis of 11 trials (N=1,020) confirmed oral TXA's superiority over placebo, with a pooled mean MASI reduction of 2.08 points (95% CI: 1.23 to 2.94) [13].

The dose matters. Most evidence supports 250 mg twice daily (500 mg total daily), which balances efficacy with a low side-effect profile. Higher doses have not shown proportionally better results. Common side effects include mild gastrointestinal discomfort and, rarely, menstrual irregularity. The theoretical concern about thromboembolic risk has not materialized in melasma trials. The Singapore RCT found no difference in thromboembolic events between TXA and placebo groups [12].

Dr. Pearl Grimes, a clinical professor of dermatology at UCLA, has noted: "Oral tranexamic acid fills a real treatment gap for patients who have failed topical therapy or have recurrent melasma that is difficult to maintain with creams alone. The safety profile at 250 mg BID is reassuring" [14].

Contraindications include active thromboembolic disease, history of deep vein thrombosis or pulmonary embolism, and concurrent use of combined hormonal contraceptives (the combination may increase clotting risk). A complete blood count and basic metabolic panel before starting, plus periodic monitoring, represent prudent practice [11].

Sunscreen: The Treatment That Makes Every Other Treatment Work

No melasma regimen succeeds without rigorous photoprotection. This is not an overstatement. A randomized trial of 200 melasma patients in Brazil found that those using broad-spectrum SPF 50+ sunscreen with iron oxide experienced a 15% greater MASI score improvement compared to those using the same SPF sunscreen without iron oxide [15]. The iron oxide component blocks visible light, which tinted mineral sunscreens typically provide.

The 2024 Joint AAD/AAFP guidelines on melasma management state: "Broad-spectrum sunscreen with SPF 30 or higher, applied daily and reapplied every two hours during sun exposure, is the single most important intervention for both treatment and prevention of melasma recurrence" [10].

Practical recommendations for patients include applying a nickel-sized amount (approximately 1/4 teaspoon) to the face every morning, regardless of weather or indoor status. Visible light penetrates windows. Reapplication every 2 hours during outdoor exposure is standard. Tinted formulations containing iron oxide provide superior visible-light protection compared to non-tinted chemical or mineral sunscreens [15].

Wide-brimmed hats (minimum 3-inch brim) provide additional 50% UV reduction to the face. For patients with stubborn or recurrent melasma, combining sunscreen with physical barriers is the minimum expectation.

Second-Line and Adjunctive Therapies

When triple combination cream and sunscreen produce incomplete results, several evidence-backed options exist.

Azelaic acid (15% or 20%) inhibits tyrosinase and is safe in pregnancy, making it the go-to option for pregnant patients who cannot use hydroquinone or tretinoin. A randomized trial found 20% azelaic acid comparable to 4% hydroquinone at 24 weeks, with 65% of patients in each group achieving good or excellent improvement [16].

Chemical peels with glycolic acid (30% to 70%) or salicylic acid (20% to 30%) improve topical agent penetration and provide modest standalone depigmenting effects. A split-face study of serial 35% glycolic acid peels combined with a modified Kligman formula showed significantly greater MASI improvement on the peel side vs. topical alone at 12 weeks [17]. Peels should be performed every 2 to 4 weeks for a series of 4 to 6 treatments.

Cysteamine cream (5%) is a newer depigmenting agent that inhibits melanin synthesis through multiple pathways. A double-blind RCT of 50 patients showed cysteamine 5% cream applied for 16 minutes daily achieved comparable depigmentation to the Kligman formula at 16 weeks, without the irritation concerns [18].

Topical tranexamic acid (2% to 5%) can be used as an adjunct to other topicals. While less effective than the oral form, topical TXA avoids systemic absorption concerns and can be used long-term. A systematic review found topical TXA reduced MASI scores by approximately 40% when used for 8 to 12 weeks [13].

Laser and light therapies require caution. Low-fluence Q-switched Nd:YAG (1064 nm) laser has shown benefit in some trials but carries a risk of rebound hyperpigmentation, particularly in darker skin types. The AAD recommends reserving laser therapy for refractory cases under the care of a board-certified dermatologist experienced in treating pigmented skin [10]. Intense pulsed light (IPL) is generally not recommended for melasma due to high recurrence rates and risk of post-inflammatory hyperpigmentation.

Melasma in Pregnancy

Pregnancy-related melasma develops in up to 50% of pregnant women, with onset typically in the second or third trimester when estrogen and progesterone levels peak [1]. The condition resolves spontaneously within 12 months postpartum in roughly one-third of patients.

Treatment options during pregnancy are limited. Hydroquinone, tretinoin, and oral tranexamic acid are all contraindicated or not recommended. Safe options include azelaic acid (FDA Category B), sunscreen, and gentle vitamin C serums (L-ascorbic acid 10% to 20%) [6]. Glycolic acid peels at concentrations below 35% are generally considered safe during pregnancy, though many dermatologists prefer to delay elective cosmetic procedures until postpartum.

Breastfeeding patients have similar restrictions. Hydroquinone absorption is minimal with topical use, but data during lactation are insufficient to recommend routine use. Azelaic acid remains the preferred active depigmenting agent during breastfeeding [6].

Maintenance and Recurrence Prevention

Melasma is chronic and recurrent by nature. Over 50% of patients who achieve clearance will relapse within one year if all treatment is stopped [2]. A maintenance strategy is not optional.

Effective long-term maintenance typically includes daily tinted broad-spectrum sunscreen with iron oxide, a topical retinoid (tretinoin 0.025% or adapalene 0.1%) two to three nights per week, and intermittent use of a tyrosinase inhibitor such as azelaic acid 15%, vitamin C, or arbutin on alternating nights [10]. Some clinicians cycle hydroquinone 4% for 8 weeks on, 4 weeks off to minimize ochronosis risk while maintaining suppression.

Hormonal management deserves attention. Switching from combined oral contraceptives to a progestin-only method or non-hormonal contraception may reduce recurrence in hormonally sensitive patients. For those on hormone replacement therapy, discussing the melanogenic risk with the prescribing provider is appropriate [6].

Melasma management is a years-long commitment. Patients who understand this from the outset are far more likely to adhere to maintenance regimens and avoid the frustration cycle of clearance followed by relapse.

How Melasma Differs from Other Pigmentation Disorders

Post-inflammatory hyperpigmentation (PIH) follows a specific injury (acne lesion, burn, eczema flare) and fades over months without hormonal influence. Melasma has no identifiable injury and worsens with hormonal and UV triggers. Solar lentigines ("sun spots") are discrete, well-demarcated macules that do not fluctuate with hormones and respond well to cryotherapy or IPL, neither of which is first-line for melasma [2].

A dermatoscopic exam can help differentiate. Melasma shows a diffuse, reticular brown network with increased vascularity. Solar lentigines show a uniform moth-eaten border pattern. PIH often has a violaceous or grey hue depending on depth. When the diagnosis is uncertain, a punch biopsy showing increased epidermal melanin with melanophages in the dermis confirms melasma [4].