Results should reflect call to action
Photoprotection misconceptions
At the meeting, Dr. Luke also discussed three misconceptions of photoprotection in skin of color, drawn from an article on the topic published in 2021.
- Myth No. 1: Endogenous melanin provides complete photoprotection for Fitzpatrick skin types IV-V. Many people with skin of color may believe sunscreen is not needed given the melanin already present in their skin, but research has shown that the epidermis of dark skin has an intrinsic sun protection factor (SPF) of 13.4, compared with an SPF of 3.3 in light skin. “That may not provide them with full protection,” Dr. Luke said. “Many dermatologists are not counseling their skin of color patients about photoprotection.”
- Myth No. 2: Individuals with skin of color have negligible risks associated with skin cancer. Skin cancer prevalence in patients with skin of color is significantly lower compared with those with light skin. However, people with skin of color tend to be diagnosed with cancers at a more advanced stage, and cancers associated with a worse prognosis and poorer survival rate. An analysis of ethnic differences among patients with cutaneous melanoma that drew from the Surveillance, Epidemiology, and End Results (SEER) program found that Hispanic individuals (odds ratio [OR], 3.6), Black individuals (OR, 4.2), and Asian individuals (OR, 2.4), were more likely than were White individuals to have stage IV melanoma at the time of presentation. “For melanoma in skin of color, UV radiation does not seem to be a major risk factor, as melanoma tends to occur on palmar/plantar and subungual skin as well as mucous membranes,” Dr. Luke said. “For squamous cell carcinoma in skin of color, lesions are more likely to be present in areas that are not sun exposed. The risk factors for this tend to be chronic wounds, nonhealing ulcers, and people with chronic inflammatory conditions.” For basal cell carcinoma, she added, UV radiation seems to play more of a role and tends to occur in sun-exposed areas in patients with lighter Fitzpatrick skin types. Patients are more likely to present with pigmented BCCs.
- Myth No. 3: Broad-spectrum sunscreens provide photoprotection against all wavelengths of light that cause skin damage. To be labeled “broad-spectrum” the Food and Drug Administration requires that sunscreens have a critical wavelength of 370 nm or below, but Dr. Luke noted that broad-spectrum sunscreens do not necessarily protect against visible light (VL) and UV-A1. Research has demonstrated that VL exposure induces both transient and long-term cutaneous pigmentation in a dose-dependent manner.
“This induces free radicals and reactive oxygen species, leading to a cascade of events including the induction of pro-inflammatory cytokines, matrix metalloproteinases, and melanogenesis,” she said. “More intense and persistent VL-induced pigmentation occurs in subjects with darker skin. However, there is increasing evidence that antioxidants may help to mitigate these negative effects, so we are starting to see the addition of antioxidants into sunscreens.”
Dr. Luke recommends a broad-spectrum sunscreen with an SPF of 30 or higher for skin of color patients. Tinted sunscreens, which contain iron oxide pigments, are recommended for the prevention and treatment of pigmentary disorders in patients with Fitzpatrick skin types IV-VI skin. “What about adding antioxidants to prevent formation of reactive oxygen species?” she asked. “It’s possible but we don’t have a lot of research yet. You also want a sunscreen that’s aesthetically elegant, meaning it doesn’t leave a white cast.”
Dr. Luke reported having no relevant disclosures.