Sunscreen: What You Don’t Know Could Harm You

Written by Lindsey Hunter-Ellul, MD on July 22, 2022 No Comments


Knowledge is power. The more you know about sun protection, the more you reduce your risk of sunburn, premature aging, and skin cancer. What you don’t know about sunscreen could surprise you. Protect yourself and your loved ones by learning more.

What Exactly is Sunburn and Why is it Harmful? 

When skin is exposed to too much ultraviolet radiation (UV light), it attempts to protect itself by launching an inflammatory response. Fair skin with less pigment will burn sooner, but all skin types are vulnerable to damage from UV radiation.

By the time skin tans, turns red, swells, becomes tender to the touch or blisters, the DNA in your skin has already been damaged.

DNA damage leads to early-onset aging. Skin develops sun spots, loses elasticity and forms wrinkles. Damaged DNA also puts you at risk for skin cancer.

It’s important to understand that skin damage and skin cancer don’t always immediately follow one another. Sunburn in childhood can double your risk for melanoma in later life. Melanoma is the deadliest type of skin cancer. Any degree of tanning or sunburn is harmful.

Does SPF Really Matter? If So, What Should I Look For?

Yes, there’s really a difference between SPF 15 and 75. That said, the higher the SPF you are comparing, the smaller the difference. For the best protection, choose an SPF of 30 or above and regularly reapply. Remember, no sunscreen offers 100% UV protection. Here’s what to look for:

  • SPF 30 or above (30 will give you 97% UVB protection)
  • Broad spectrum sunscreen that offers both UVA and UVB protection
  • Water and sweat resistant formulas (you’ll still need to reapply)

Mineral based sunscreens block, or reflect the sun off of your skin with inorganic minerals, such as zinc oxide or titanium dioxide. This type of sunscreen starts working as soon as you put it on.

Chemical based sunscreens protect you with organic chemicals, such as avobenzone and octinoxate, form a thin film that absorb and break down UV radiation before penetrating the skin, converting this energy to heat. This type of sunscreen must be applied 15-30 minutes prior to sun or water exposure to ensure proper absorption into the skin!

Sunscreen now comes as a cream, lotion, powder, spray, or stick, to name a few. There are sunscreens for all skin types, including light or dark skin, sensitive skin, and even oily skin. You’ll also find make-up, lip balms and other products with sunscreen in them.

The sunscreen you find easiest to apply, and the one you’re most likely to use is the best one!

Should Adults Use Different Sunblock Than Kids?

Sometimes we find it easier to pack sunscreen for our kids than to remember it for ourselves. So, it’s tempting to lather up with their lotion when we finally remember that we need it too. The good news is, we can!

When choosing sunscreen for your kids, keep these tips in mind:

  • Babies up to 6 months old: There is no FDA-approved sunscreen for children under 6 months old. It’s safest to keep your baby in the shade.
  • Kids 6 months – 2 years: For children up to 2 years of age, only mineral-based sunscreen is recommended. Young kids may be sensitive to chemical formulas.
  • Kids over 2 years old: While adults and older kids can use chemical sunscreens, mineral-containing formulas are recommended for those who’ll be in the water or sweating a lot. Combination products (mineral and chemical-containing sunscreens) work great.

How Often Should I Reapply? 

Sunscreen isn’t a one-and-done solution. Even the highest SPF formulas will last at most about 2 hours. If you’re in the water, you can cut that time in half, despite using water-resistant sunscreen. There is no such thing as water proof sunscreen.

Pay attention to how long you’ve been in the sun and set a timer to remind you when to reapply. If you’re using a chemical formula, keep in mind it may take up to 30 minutes to absorb into your skin and start working.

Always reapply to clean, dry skin. An average sized adult requires approximately one shot-glass sized amount for total body protection per application!

Sun Protection Advice from a Dermatologist

Sunscreen is just one small part of sun protection. Staying in the shade under an umbrella, awning or other structure protects your skin from sun damage. So too does UV-protective clothing, hats and sunglasses.

  • Choose a wide-brimmed hat to protect your ears and the back of your neck
  • Select UV-protective sunglasses to reduce damage to your eyes and delicate eyelid skin
  • SPF clothing is breathable, lightweight and tightly woven to help shade screen from sun

Not all clothing protects you from the sun. You can easily get burned through a cotton t-shirt, mesh, linen or other loosely woven fabrics. If you’re relying on your clothing alone to protect you, make sure it’s SPF-rated or apply sunscreen underneath your clothes.

You can still get burned through a window. Just being indoors won’t protect you from UVA rays. You might still need sunscreen if indoors, and especially while driving.

You can still get burned on cloudy days. Up to 80% of harmful UV radiation is capable of penetrating cloud cover. Clouds are not the same as shade protection.

Yes, the sun is sometimes stronger. The UV index is a measure of your sunburn risk. UV strength depends on the weather, time of year, elevation, latitude and ozone levels. In Texas, the summer sun is at its peak strength between 10am and 2pm. This is the time to stay most vigilant – it doesn’t mean you’re not at risk for sunburn outside of these hours.

Schedule an annual skin check. Skin cancer is best treated when diagnosed early. It can show up anywhere on your body. The most dangerous forms of skin cancer can even appear where you haven’t been exposed to the sun. An annual visit to your dermatologist can help keep you, and your skin, healthy!

Lindsey Hunter-Ellul, MD

Lindsey Hunter-Ellul, MD, FAAD is a Board Certified Dermatologist and is recognized as a Texas Monthly Super Doctors Rising Star. She has years of experience in medical dermatology, skin cancer, procedural and cosmetic dermatology, treating patients of all ages and skin types. Dr. Hunter-Ellul has served on several committees for the American Academy of Dermatology, Texas Dermatological Society, and was the Physician Editor for the AAD Directions in Residency Newsletter.

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