Melasma Mitigation: It All Begins with Photoprotection

Melasma is a chronic condition that causes patches of darker skin on the face with repeated exposure to the sun. According to Susan Taylor, MD, Bernett Johnson Endowed Professor of Dermatology at the University of Pennsylvania Perelman School of Medicine, the appearance may fluctuate over time and while treatment can help improve appearance, it may not completely eliminate it.

Taylor offered her expertise and guidance on the condition in a presentation at the 2025 Midwinter Clinical Hawaii Dermatology Conference, February 15-29, 2025, on the Big Island, Waikoloa Village, HI, aptly titled, It all Begins with Photoprotection.

Melanogensis

The process of melanogenesis is activated by factors such as ultraviolet (UV) and visible light (VL) radiation, medications, and genetic factors, Taylor said. In technical terms, the process involves the conversion of tyrosine to melanin, which is then transported to surrounding keratinocytes. Overproduction of melanin results in dyschromias, including melasma. In her discussion, Taylor covered several related key topics including the effects of the sun on skin, types of filters available (ie, sunscreens), FDA regulation of ingredients of sunscreens, and recommendations on personalized guidance for patients. Following are highlights from the presentation.

Effects of Solar Radiation

• Ultraviolet Radiation (UVR): Comprises UVA, UVB, and UVC. UVA penetrates deeper layers of the skin, causing matrix collagen degradation and oxidative stress, causes immediate and persistent pigment darkening especially in darker skin types. UVB leads to erythema and pigmentation, while UVC is mostly absorbed by the ozone layer.
• Visible Light (VL): Constitutes 50% of electromagnetic radiation (EMR) and has significant effects on skin pigmentation, especially in darker skin types (Fitzpatrick Skin Types III-VI). It causes erythema, and damage to the dermal matrix. Blue light (high energy visible light, HEVL) increases reactive oxygen species (ROS) and activates tyrosinase, leading to hyperpigmentation.
• Infrared Radiation (IR): Causes skin darkening and contributes to skin aging.

Taylor shared findings from a study that found 43% of US dermatologists reported that they never, rarely, or only sometimes take patients’ skin type into account when they make sunscreen recommendations. She recommended discussing sun protection with patients based on Fitzpatrick skin type susceptibilities, any underlying cutaneous disorders, lifestyle and extent of exposure (eg, workplace). She also emphasized the importance of ensuring that joint decision making with patients is culturally appropriate.

Photoprotection Strategies

• Sunscreens: Active ingredients are classified as UV filters, which include inorganic filters like titanium dioxide and zinc oxide, and organic filters such as avobenzone and octocrylene. Inorganic filters provide broad-spectrum protection but may have a chalky appearance.
• Iron oxides: Added to sunscreens to reduce VL transmission and provide additional protection against hyperpigmentation. Most effective VL sunscreens contain iron oxide concentrations greater than 3% but they are typically listed as inactive ingredients.

Taylor described a study of 68 adults with melasma who used sunscreen with UV and VL protection of with UV protection alone. The UV-VL treatment group had a 77.8% improved Melasma Area and Severity Index (MASI) score compared with a 61.9% improvement in the UV-only sunscreen group. 

Systemic Absorption of Sunscreen Ingredients

Studies have shown that certain organic filters exceed the FDA threshold for systemic exposure, raising concerns about potential toxicological effects. However, inorganic filters like zinc oxide and titanium dioxide are generally considered safe as they do not penetrate below the stratum corneum.

Photoprotection in Specific Populations

• For dyschromias. Use broad-spectrum photostable sunscreen that is tinted and contains a blend of iron oxides and pigmentary titanium dioxide to reduce VL transmission or contains certain antioxidants agents (reduce VL-induced effects by decreasing reactive oxygen species).
• For vitiligo. UV exposure for progressive vitiligo is not recommended; patients should follow strict sunscreen regimens; tinted sunscreens or color correcting sunscreens can help to camouflage depigmented areas.

However, Taylor reviewed the findings of a literature search by an international panel that reported while sunburn may provoke vitiligo, UV exposure is critical for repigmentation of lesions. According to the consortium, patients with stable disease should regularly expose lesional skin, while protecting normal skin, to sun until the lesions become pink; then, apply high SPF broad spectrum sunscreen to prevent sunburn.

Consider polypodium leucotomos extract (PLE)

Polypodium leucotomos (PL) is a fern found in Central America; the extract, (PLE) has demonstrated photoprotective effects when taken orally or applied topically.

• In healthy volunteers, oral PLE supplementation increased the UV dose necessary for immediate pigment darkening (IPD) and minimal erythema dose (MED) with oral PLE supplementation. In Asian adults with facial melasma PLE supplementation significantly improved melasma outcomes when combined with hydroquinone and SPF 50+ sunscreen. In patients at high risk for melanoma, PLE increased MED in all participants including those with familial or multiple melanomas, sporadic melanoma, and atypical mole syndrome, with 65% of subjects exhibiting increased MED. In patients with polymorphic light eruptions PLE reduced lesion severity. In people with darker skin types, PLE supplementation decreased effects of visible light, including persistent pigment darkening and delayed tanning.

Recommendations for Photoprotection

• Broad-spectrum sunscreens: Use sunscreens with a critical wavelength of 370+ nm to protect against UVB and UVA2-induced skin damage.
• Tinted sunscreens: Consider tinted sunscreens containing iron oxides for additional VL protection and cosmetic benefits.
• Lifestyle and environmental factors: Advise patients to seek shade, wear protective clothing, and avoid midday sun exposure.

Effective photoprotection requires a comprehensive approach, including the use of broad-spectrum sunscreens, consideration of individual skin types, and awareness of systemic absorption risks. Taylor emphasized the importance of ongoing research to better understand the long-term effects of sunscreen ingredients as well as the potential benefits of novel photoprotective agents like PLE.