By Lisa Rapaport

(Reuters Health) – When applying sunscreen, people tend to miss spots on their faces, and a new study suggests this is even more likely when they use SPF moisturizers.

Many moisturizers contain ingredients that offer a sun protection factor (SPF) comparable to what can be found in sunscreens, and in theory both options could offer similar protection from harmful ultraviolet (UV) rays.

While previous studies have found that people don’t use enough sunscreen around their eyes, less is known about how thoroughly people apply SPF moisturizers, the study authors note in PLoS ONE.

To find out, the researchers invited 84 people to make two laboratory visits. In one visit, they were asked to apply sunscreen on their faces, and at the other, an SPF moisturizer. Before and after these applications, researchers exposed participants to UV radiation and took photos using UV-sensitive cameras to show whether they had fully protected their face using the sunscreen or moisturizer.

Overall, 17 percent of participants, or nearly one in five, failed to cover their entire face when using SPF moisturizer, while 11 percent, or about one in 10, failed to accomplish this goal with sunscreen.

This difference was primarily due to decreased coverage around the eyes: about one in six participants missed regions around the eyelids with sunscreen, as did one in five participants using SPF moisturizers.

“We expected the eyelid areas to be better covered by moisturizer compared to sunscreen as we thought the perception would be that moisturizers would cause less eye stinging if they accidentally seeped into the eyes, or we expected to find no difference between the two,” said senior study author Austin McCormick of Aintree University Teaching Hospital in Liverpool, UK.

“Instead, we found that when using moisturizer with SPF, less facial area was covered and in particular the eyelid area was missed to a greater extent,” McCormick said by email. “This is important because the eyelids are a common site for skin cancer.”

Participants were largely unaware that they had missed spots with sunscreen or SPF moisturizer, leaving areas of the face that are at higher risk for cancer unprotected, the study authors note.

It’s possible that people were more careful with sunscreen than with moisturizer because they use these things differently in their daily routines, said Dr. Elizabeth Martin, president of Pure Dermatology & Aesthetics in Hoover, Alabama, who wasn’t involved in the study.

“Perhaps there is a difference here because when people think about applying sunscreen they know they are going to be putting it on for a purpose – to protect themselves from the sun – and perhaps they are a little less diligent with moisturizer with SPF as it is part of their daily routine, without considering sun exposure,” Martin said by email.

Some participants might also use separate moisturizers for their eye area, and deliberately skip using the SPF moisturizer around the eyes for that reason, Martin said.

Because they may miss some spots, it’s critical for people to take other steps to protect their face from the sun, including hats and sunglasses with UV protection, Martin advised.

Whatever form of SPF moisturizer or sunscreen people use, they need to reapply every couple of hours while they’re active outdoors, said Dr. David Leffell, a skin cancer specialist at Yale School of Medicine in New Haven, Connecticut, who wasn’t involved in the study.

“Moisturizer with SPF does not take the place of sunscreen or other good sun protection practices,” Leffell said by email. “People should use a sunscreen with an SPF of 30 or 50 but more than 50 is generally not necessary and less than 30 is similarly not sufficient in my opinion.”

SOURCE: https://bit.ly/2Vl0lyD PLoS ONE, online April 3, 2019.