Applying Sunscreen: Are You Doing It Wrong?

You’ve gotten the message about the importance of sun protection, you’re stocked up on sunscreen that’s at least 15 SPF, and you’re diligent about putting it on before you head outside. Once you’ve gotten this far, there’s no reason to risk sunburns by applying it incorrectly. But, all too often, that’s exactly what happens, says a Saint Louis University dermatologist.

Dr. Quenby Erickson examines skin cancer cells under a microscope.

“I’ve seen mothers at the park spraying sun block on babies from too far away to do enough good,” said Quenby Erickson, D.O., a SLUCare dermatologist and Mohs surgeon. “Others dab on too little to protect themselves adequately from the sun’s rays.

“If you’ve gone to the admirable effort of buying and applying sunscreen, make sure it’s working while you wear it.”

Erickson warns against the following mistakes and offers tips for making sure your sunscreen is working:

Too Little: Lather it on! Adults need the equivalent of a shot glass full of sunscreen to cover their whole body. And be sure to cover all skin that’s exposed to the sun. Don’t forget about your ears, back of your neck, tops of your feet, and, if you’re balding, the top of your head.

Too Late: Timing is important. Apply sunscreen 30 minutes before heading outdoors, and reapply every two hours and after swimming.

Too Far Away: If you’re spraying a child at arm’s length, you’re probably not giving him or her complete protection from the sun’s rays. Aim the spray bottle two to three inches away from the body. It’s also important to rub spray sunscreen into the skin for full coverage.

Too Old: Sunscreen has an expiration date, and it can be less effective if it’s past its prime. If you’re using the recommended amount of sun block, it’s less likely to sit on the shelf long enough to expire. An adult should get around four uses per bottle.

SLUCare, the physician practice of Saint Louis University School of Medicine, is the only academic medical practice in St. Louis that is fully accredited by the Accreditation Association for Ambulatory Health Care Inc. This accreditation is a voluntary process through which the quality of SLUCare services and performance is measured against nationally recognized standards. To schedule an appointment, call 314-977-4440. More information is available at

Carrie Bebermeyer