Sunscreen is a product almost all dermatologists recommend on a daily basis in clinic, and Roger Ceilley, MD, presented what’s going on behind the scenes in this industry as the United States lags behind other countries in available protective UV filters. Currently, the FDA is requiring additional data on a dozen different chemicals to prove them generally safe and effective. More studies are required to determine the quantity of detectable filters in the blood after application before the FDA will give the official approval on many ingredients already approved in Europe, though companies are not required to remove products from the market until the FDA has given their final word on the ingredients within. Of the 17 filters currently approved in the US, 5 are not commonly used, leaving us with 12 compared to almost 30 in the EU. A primary difference between the chemicals available in the US compared to the EU is that we have fewer ingredients that provide protection against UVA1 (340-400 nm), which plays a large role in photoaging, and these include zinc oxide, titanium dioxide, and avobenzone, the last of which still awaits the FDA’s final verdict. It is not uncommon for patients to look for sunscreen abroad where they have access to more filters such as Mexoryl SL/XL/400, Tinosorb S/M, and TriAsorB.
However, Dr Ceilley assured us that new filters in the US are on the way, such as bemotrizinol (BEMT), which is currently undergoing FDA approval and would be the first in over 2 decades. He also presented absorption graphs for TriAsorB, Mexoryl 400, and another novel filter for the EU, BDBP. Moving on to more clinical implications of the sunscreen industry, Dr Ceilley discussed melasma and the importance of photoprotection beyond just sunscreen like photoprotective clothing. The photobiologic impact of visible light has also been a hot topic within the past year, and it, along with UVA1, may aggravate conditions driven by sun exposure like melasma and postinflammatory hyperpigmentation. Tinted sunscreens and oral agents are the best tools against these longer light wavelengths, especially before new filters come to the market. However, tinted sunscreens aren’t as inclusive for all skin types as they should be, especially since Fitzpatrick types IV-VI may benefit more from protection against UVA and visible light, compared to Fitzpatrick types I-III which require UVB protection as well, broadly speaking. An extract from a fern plant native to Central America, Polypodium leucotomos, has been shown to downregulate visible light and UVA1-induced pigmentation and can be recommended as an important adjunct treatment.