Following his session, “Photoprotection Updates,” presented at the 2024 Winter Clinical Dermatology Conference in Hawaii, Dr Brandon Adler shared the latest updates in sunscreen usage, how physicians can implement these changes in their practices, and the challenges that come with managing patients using photoprotection.

Brandon Adler, MD, works in Los Angeles, CA, as a board-certified dermatologist. He is affiliated with Keck Hospital of USC. He specializes in contact dermatitis and provides comprehensive patch and photopatch testing and evaluation of sun-sensitive skin disorders. He is a member of the North American Contact Dermatitis Group and serves on the board of directors of the American Contact Dermatitis Society.

What were the highlights covered during your session, “Photoprotection Updates”?

Dr Adler: We focused primarily on a couple of key areas, those being updates in sunscreen safety and emphasis on the usefulness of protection from visible light for certain conditions and patient populations. And then a review of oral photoprotection strategies. Since we focus so much on topical, it's nice to look at the oral options and the evidence for those.

What are the newest updates for photoprotection that physicians can look forward to or implement their practice?

Dr Adler: In terms of sunscreen safety, which was the big centerpiece of the talk, we reviewed the updated information. Sunscreens have been considered by the FDA to fall into 3 different categories. One is GRASE or generally recognized as safe and effective, and that's our physical or mineral sunscreens, zinc oxide and titanium dioxide. Another is not GRASE, meaning they're not generally recognized as safe. That's fortunately only 2 sunscreens, trolamine salicylate and para-aminobenzoic acid (PABA), which are no longer marketed in sunscreens in the United States. And then all the other available sunscreen active ingredients fall under the category of additional data needed to determine their GRASE status. But this doesn’t imply any harms associated with their use. Going from there, what we briefly went into in the talk was that there's an enhanced focus on the safety of the sunscreens that we're putting on our skin every day.

We've been using sunscreens for many years, but we're using them more and more. We're counseling patients to apply sunscreens and reapply them daily. There's evidence that the exposure to the chemical sunscreen filters is very high, and this has been confirmed by the FDA in some studies that were conducted under their auspices that showed without a doubt that there is systemic absorption of the chemical sunscreen filters above a predetermined cutoff that triggers the need to obtain additional safety data. Which can sound very scary both to the public and even to medical providers, but the big picture is there's absolutely no evidence in high-quality human studies of any harms associated with the use of sunscreen to the present day. So, this creates situations where, of course, there's some uncertainty for concerned individuals. The 2 GRASE sunscreens, zinc oxide and titanium dioxide, have the most safety data. For me personally, I do agree that there's a need to obtain additional information based on this finding of systemic absorption, but it seems less likely that there is a major safety signal involved here. I continue to use these sunscreens regularly myself. We need to look into it more rigorously, for sure.

In your experience, what are the challenges and considerations when managing patients utilizing photoprotection?

Dr Adler: One challenge can be navigating all this information like what's okay versus what's not when it comes to sunscreens. The next thing that we moved into that I think falls under this question is the environmental safety of sunscreens. One of the big concerns has been, are sunscreens causing coral bleaching? We're seeing a lot of sunscreens that have this reef safe or reef friendly label on them these days. So, this all comes primarily from a study done in 2016 that showed there was a concentration dependent mortality and potentially a bleaching signal for coral larvae, the most vulnerable forms of coral, when exposed to oxybenzone, one of the most common chemical sunscreens, in a laboratory environment and an artificial setting. Now, we take the environment very seriously in dermatology and there's an increasing focus on sustainability of our practices and impact on the greater planet.

What I highlight is that this study has been criticized as delivering an acute exposure to the most vulnerable forms of coral with an unrealistic concentration of oxybenzone versus the levels detected in most studies from the real-world environment. More recent studies have shown that it's a more nuanced picture. By far the number 1 factor contributing to the damage to our coral reefs and coral bleaching is climate change and ocean warming. The chemical sunscreens may potentially add insult to injury, so to speak, as a more minor secondary effect. So, for our concerned patients, or concerned individuals, the answer is sort of similar to our first topic where the zinc and titanium-based sunscreens seem to have little to no impact when it comes to environmental health. Then the bigger picture, the elephant in the room, is that this is all about climate change and sunscreen is likely a very small piece of the puzzle regardless. Some chemical sunscreens, including oxybenzone, have been banned in certain localities, including Hawaii, where we just were. It's a complicated picture. At the end of the day, I think everybody wants the best for our planet as we move into a complex future together, but I think the real-world evidence really supports that sunscreen is a smaller part of the picture.

What else would you like to share with your colleagues regarding your session at Winter Clinical Hawaii 2024?

Dr Adler: The last 2 big points were, number 1, that visible light or the light that we can literally see has been traditionally ignored in our photoprotection strategy. We've learned more and more that for our patients with pigmentary disorders and patients with skin of color, visible light affects a number of important cutaneous endpoints. It has been highlighted increasingly that visible light protection can help to improve the course of such common conditions as melasma. The big takeaway here is that our routine sunscreens that you can get off the shelf, whether it's a chemical blocker or a mineral or physical blocker, don't do a great job at providing visible light protection. So, the way to go here is with tinted sunscreens that have added iron oxides, which give a  literal pigment to the sunscreen that can be tailored to the patient's skin tone and helps to block out the effects of visible light on the skin and improve the course of melasma and other pigmentary disorders.

The last thing we highlighted was evidence for oral photoprotection strategies. We went through these based on higher vs lower quality evidence. We talked about oral acitretin, one of our old school systemic retinoids, which has got some pretty good evidence in randomized trials, particularly with our high-risk skin cancer patients and organ transplant patients. For more routine situations, we talked about Polypodium leucotomos extract, which is an over-the-counter antioxidant supplement that has been shown, in some studies, to decrease erythema and signs of damage after exposure to ultraviolet radiation. We talked about oral nicotinamide, which has been shown in a randomized study to reduce the outcomes of non-melanoma skin cancer, as well as actinic keratoses in immunocompetent, but not organ transplant individuals. We highlighted that a number of other over-the-counter supplements and vitamins have been proposed to potentially help with photoprotection from an oral administration point of view, but with much more limited evidence. So, we reviewed overall the updates as far as sunscreen safety for humans and for the environment. We talked about a new photoprotection strategy, particularly for our patients with pigmentary disorders and skin of color. Finally, we reviewed, briefly, the evidence for a variety of oral photoprotection strategies.