11 Sunscreen Questions Answered by a Dermatologist

Sunscreen can save your life if you know how to use it effectively.

The truth is that far too many people suffer from sun-caused skin ailments like signs of aging, dark spots, and even worse, skin cancer

Here to walk us through sunscreen is Dr. Lauren Karpinski.

About Dr. Karpinski

Dr. Karpinski grew up in Brecksville, Ohio and attended Miami University for her pre-medical training. During her time at Miami University, she studied Zoology and Neuroscience and received multiple awards for her research in the field of Neurobiology. Dr. Karpinski returned to Northeast Ohio to attend medical school at Case Western Reserve University School of Medicine. Her interest in Dermatology quickly became her passion, and she delved into research focusing on new and innovative techniques for pre-cancer and skin cancer treatment.

Dr. Karpinski then completed her Transitional Medicine/Internal Medicine Internship at Summa Akron City Hospital and her Dermatology Residency at University Hospitals of Cleveland. During her Dermatology Residency, she continued her research endeavors with a hospital-wide project that helped to improve the care of patients with chronic skin conditions of the lower legs. Dr. Karpinski trained with several leaders in the fields of medical, aesthetic, and surgical Dermatology. She sees both adult and pediatric patients for a wide variety of skin conditions.

1. What are the main ingredients of sunscreen?

 

“The active ingredients in sunscreens are classified as either “physical blockers” (e.g. zinc oxide, titanium dioxide) or “chemical absorbers” (e.g. avobenzone, PABA, octocrylene). Sunscreens form a coating on the surface of the skin that prevents harmful rays from reaching the living epidermis and dermis.”

Sunscreens classified as “physical blockers” work by reflecting damaging ultraviolet light rays away from the skin and body. Sunscreens classified as “chemical absorbers” work by converting damaging ultraviolet light rays into non-damaging energy. 

“Most sunscreens contain a combination of two or more of these agents to offer high levels of protection against both UVA and UVB light; these are known as “broad-spectrum” sunscreens.”

 

2. What is the difference between UVA and UVB light?

 

 

“Scientifically, UVA and UVB light are both forms of ultraviolet light produced by the sun but of different wavelengths. While UVB light is most damaging to the skin in terms of sunburn, development of non-melanoma skin cancer, and skin aging. 

UVA light is able to penetrate the skin more deeply and there is 10-20 times as much UVA as UVB in sunlight. This is why it is important to look for “broad-spectrum” sunscreens, which offer the best protection against both of these forms of damaging ultraviolet rays.

 

3. What does SPF level mean?

SPF stands for Sun Protection Factor. This stands for the amount of protection a specific sunscreen will provide.

“When properly applied, a sunscreen product with an SPF of 15 would allow you to spend 15 times as much time in the sun before developing the skin redness that would have appeared if you had not applied sunscreen at all.”

 

4. How much sunscreen should I be applying?

 

“Research shows that individuals do not apply sunscreen as thickly as when SPF testing is being performed during the development of a sunscreen product. Most sunscreen users only apply 25-75% of that quantity.

“Applying only one-half the standard amount of an SPF 30 product will then reduce the protection level by half; so it is as if you applied a sunscreen product of SPF 15 instead.

“This is why cosmetic products (e.g. foundation, powder) containing sunscreen are not sufficient on their own. The proper amount of sunscreen required to cover the skin of an adult is approximately two tablespoons or one full shot glass. This is also why applying a product of higher SPF will give you greater protection against burns, as areas where it may have been applied in too thin of a layer will still retain a high SPF level of protection.”

 

5. Is spray sunscreen okay to use?

 

“Most individuals do not apply spray sunscreen in as thick of a layer as they would with sunscreen lotion. 

Spray sunscreen can be used as long as the product covers the skin completely, which often requires applying enough spray sunscreen to the point of “dripping” and then smoothing the product over the skin with your hands. 

Spray sunscreen is also a great option for “parts” in the hair that are often overlooked and make the scalp prone to sunburn.”

 

6. How often should I reapply?

 

Sunscreen should be reapplied every 2-3 hours. More frequent reapplication is required if sweating or swimming. Forgetting to reapply sunscreen is the most common reason why you might still get a sunburn even if you are using sunscreen.

 

7. What type of sunscreen should I put on my kids?

 

“Sunscreen is safe to use in children 6 months of age and older. Younger infants should be protected in other ways, such as by seeking shady areas and by wearing sun-protective clothing

Most sunscreens indicate on the bottle whether they are for use in babies and children. 

These sunscreens tend to contain ‘physical blockers’ and are often formulated so that they do not cause burning or stinging of the eyes.”

 

8. How do I choose the best sunscreen for me?

 

 

9. What is the difference between regular and “sport” sunscreens?

 

“Sport sunscreens are products that “stick around” on the surface of the skin for much longer than other sunscreens. 

This allows for vigorous outdoor activity and even swimming with continued protection. But remember, even these products need to be reapplied frequently!”

 

10. Will use of sunscreen decrease my Vitamin D levels?

 

“The first step in the production of Vitamin D within the body is the conversion of Vitamin D from one chemical form to another by UVB light rays reaching the skin. Therefore, sunscreens that are effective at blocking UVB light would be expected to decrease levels of Vitamin D within the body, which does in fact occur.” 

However, research shows that while Vitamin D levels are slightly reduced in sunscreen users compared to sunscreen non-users, all these individuals generally fall within the normal range. 

Keep in mind also that there are many risk factors for low Vitamin D levels, including having a dark complexion, living in a northerly climate, being female, and during the wintertime. An appropriate diet and supplements can help return Vitamin D levels to the normal range, without increasing your risk of developing skin cancer.”

 

11. Why should I wear sunscreen every day?

 

“Sunscreen usage prevents the visible and microscopic changes that take place with aging, and daily usage can actually help reduce some of the damage that has already occurred. In fact, research has shown that daily sunscreen use can result in a significant reduction in the specific skin changes that can lead to precancerous actinic keratoses.” 

 

In order to ensure your skin is healthy and ready for the summer, book an appointment with a board-certified dermatologist. 

Dr. Karpinski made me feel very welcomed when she came into the room. I explained why I was there and she took her time looking me over and explained what everything was. She ended up doing a procedure and gave me care instructions to take home. I will be back!

Robin G. Verified Patient Apex Dermatology Medina June 21, 2019

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