Something Is Better Than Nothing, But What’s Best for Sunscreen Application?

Selected by Pietro Cazzola MD

FotoprotectionEvery spring, patients begin asking questions about which sunscreens they should use. We advise patients to follow the American Academy of Dermatology recommendations to use broad-spectrum, water-resistant, and SPF 30 or greater sunscreen. Then, patients reliably ask which vehicle is best. In this situation, our answers tend to be less explicit as the facts are not as readily known. We simply need better data to provide our patients. A recently published study by Novick and colleagues1 is the first comparison of a sunscreen vehicle’s effect on the concentration applied to the skin by the study participants. The authors measured sunscreen application with lotion and stick on the forearms of live persons and spray on a different site on simulated persons. While there are some concerns regarding comparability between application methods and other inherent limitations to the study cited by the authors, the initial concentration of spray sunscreen applied at least appears to be equivalent or better than lotion and stick sunscreens. Additionally, methylisothiazolinone, a known allergy sensitizer, was not detected in the spray or stick sunscreens tested. These findings are comforting, given almost 25% of North American sunscreens launched in 2012/2013 were spray formulations,2 and another trial observed participant preference toward alcohol-based spray formulations over gels, creams, and lotions.3
In recent years, spray sunscreens have come under scrutiny due to health concerns following inhalation. Similar concerns were raised for powder sunscreens, which were removed from the market by the FDA. While prolonged exposure to aerosolized titanium and zinc oxide for multiple hours can cause cardiopulmonary effects in animal models,4,5 the FDA and American Academy of Dermatology currently do not advise against sunscreen spray formulations given the short timeframe of aerosolized exposure. They do recommend against spraying directly on the face and suggest other steps to minimize inhalation during spraying. The FDA is still investigating the safety.
While additional trials are needed to replicate the results of Novick and colleagues and to try to standardize the application method in a real-world setting, this trial provides preliminary reassurance to healthcare providers that spray sunscreen formulations provide similar initial concentrations on the skin compared with more traditional formulations. At this time, we recommend that practitioners counsel all patients on the use of multiple concurrent photoprotective methods and advise patients to choose whichever sunscreen vehicle they are most willing to use. Additionally, we recommend all patients be advised to use adequate amounts of sunscreen and to reapply every 1 to 2 hours. Specifically patients who opt for spray formulations should be counseled to apply a thick and even coating, not spray the sunscreen directly on the face, minimize inhalation by applying outdoors, use care in the wind to prevent inadequate application and inhalation, and possibly consider an alternative vehicle if they have compromised pulmonary function or significant pulmonary disease. Until we can strongly determine that one vehicle is superior to another, it is best to support patients in any appropriate means of photoprotection to make the outdoors safe for all.

Written by James L Griffith MD and Marla N Jahnke MD