US Pharm. 2016;41(7):26-29.
Winter is over, nicer weather has arrived, and the sun is finally out! That means outings to the beach, swimming in the pool, and red, hot skin that may be painful to the touch. Almost everyone at some point has experienced the pain associated with a sunburn. Despite increasing use of protective behaviors, it is estimated that at least half of all adults in the United States experience sunburn yearly, and almost two-thirds of those will experience more than one episode in the same year.1,2
Skin Cancer
Sunburns carry with it an increased risk of developing skin cancer, the most common form of cancer in the U.S. Most of these are nonmelanoma skin cancers such as basal and squamous cell carcinomas, but the risk of melanoma is present. Sunburn at any age is associated with an increased risk for skin cancer, but the more sunburns a person experiences, the greater the risk; experiencing five or more blistering sunburns between the ages of 15 and 20 years increases an individual’s risk of developing nonmelanoma skin cancer by 68% and melanoma by 80%.3,4
Skin cancer is a major public health concern. Educational messages have focused on protection from ultraviolet (UV) radiation and the use of sunscreen and other sun protection measures. As one of the most accessible healthcare providers, pharmacists play an important role in helping patients understand the importance of sun protection, in particular sunscreen and its proper use.
UV Radiation
Sunlight is a continuous spectrum of electromagnetic radiation that is divided into three major types: UV, visible, and infrared.5 UV radiation is the one most closely associated with photoaging and skin cancer.5 It is subdivided into UVA, UVB, and UVC. Solar radiation that reaches the surface of the Earth is 95% UVA and 5% UVB; UVC rays possess the highest amount of energy but are absorbed entirely by the ozone layer.5,6 Both UVA and UVB exposure can have damaging effects on the skin, causing direct cellular damage and alterations in immunologic function. UV radiation exposure can result in sunburn, tanning, photoaging, and skin carcinomas.5,6
The amount of UV radiation that reaches the Earth’s surface is dependent on a variety of factors. UVB radiation has a greater intensity in the summer than in the winter and is at its strongest between the hours of 10 am and 4 pm. Those living closer to the equator have increased UV radiation exposure. Fog, haze, and pollutants can decrease UV levels by 10% to 90%, while snow, sand, and metal can reflect up to 90% of UV radiation.5,6
Sunscreen
One way individuals can protect themselves from the damaging effects of the sun is to use sunscreen. These products absorb, scatter, and/or reflect UV radiation to help prevent damage from the sun’s harmful UV rays. Sunscreens can be classified into two categories: physical and chemical. Physical sunscreens contain inorganic compounds that reflect and scatter the UV rays, whereas chemical sunscreens contain organic compounds that absorb the rays, preventing them from damaging the skin.7
In addition to the type of sunscreen, there are many other factors to consider when choosing or recommending a sunscreen product to patients. Some of these include the product’s sun protection factor (SPF), type of coverage, and water resistance. Terms that are no longer used to describe sunscreens include “instant protection,” “all day protection,” and “sunblock.”8
SPF Essentials
A sunscreen’s effectiveness is represented by its SPF. Many people think that a sunscreen’s SPF is related to the duration of UV exposure, allowing them to stay out twice as long in the sun. This is not true because this number represents the amount of UVB radiation needed to produce a sunburn on protected skin compared to unprotected skin.8,9
There are other factors that impact the amount of solar energy. The intensity of UVB radiation plays a role in determining the amount; time of day, geographic location, and weather conditions all influence the intensity of UVB radiation.9 It generally takes less time during midday to be exposed to the same amount of radiation compared to early morning or late afternoon. Other factors include skin type, amount of sunscreen applied, and reapplication frequency.9 Therefore, SPF is a relative measure and a good comparison of how well a sunscreen protects against sunburn; a product with an SPF 30 provides better protection than a product with an SPF 10.
It is important to recognize that doubling the SPF does not provide double the protection. A sunscreen with an SPF 15 filters approximately 93% of UVB rays, while a product with an SPF 30 filters about 97%.10 Raising the SPF to 50 provides an additional 1% coverage, blocking 98% of UVB rays.10 There are currently no scientific data to support the use of a product with an SPF higher than 50.8,11
Broad Spectrum
A sunscreen’s SPF only indicates its ability to block UVB rays; too much exposure results in a sunburn. Because UVA rays do not cause sunburn, effective blockage cannot be determined by SPF. The term broad spectrum is used to describe sunscreens that block both UVA and UVB rays. These products must pass the FDA’s broad-spectrum test procedure and possess an SPF value of at least 15 if they are claiming to reduce the risk of skin cancer and early skin aging.8 If they have an SPF with a value <15, they can only claim to help prevent sunburn.8
Water Resistance
When exposed to water, a sunscreen’s effectiveness is decreased. Those who swim or are active outdoors will need a sunscreen that will protect them during these times. The terms “waterproof” and “sweatproof” are no longer used to describe sunscreen. Based on standard testing, the term “water resistant” is used to describe those sunscreens that will remain effective at the stated SPF level after 40 minutes in the water. Sunscreens labeled as “very water resistant” are those that remain effective after 80 minutes of swimming or intense sweating.8,12 Sunscreen should be reapplied after 40 to 80 minutes after swimming or sweating, or immediately after towel-drying.
Choosing a Product
There are currently 17 active sunscreen ingredients approved by the FDA (TABLE 1). When assisting patients in choosing the appropriate product, the SPF, broad-spectrum coverage, water resistance, skin sensitivities, and cosmetic concerns should be considered. For maximal protection, the American Academy of Dermatology (AAD) recommends using a sunscreen with an SPF of at least 30 that is broad spectrum and water resistant.11 Creams are best for dry skin and use on the face, while gels are good for hairy areas.11
Adverse skin reactions are infrequent and mainly subjective, with stinging and burning being the most commonly reported complaints.13 PABA (para-aminobenzoic acid) and oxybenzone are the ingredients most commonly associated with contact dermatitis. Avobenzone, sulisobenzone, octinoxate, and padimate O have fewer associated reports, and because salicylates, ecamsule, and the physical sunscreens do not penetrate the stratum corneum, photosensitivity is uncommon.13 Patients who have predisposed skin conditions such as eczema and photodermatoses should be counseled appropriately.
Appropriate Use of Sunscreen
Sunscreen should be used in all children and adults aged ≥6 months. The AAD recommends daily, year-round use of sunscreen regardless of age and skin type. Studies have shown reductions in certain skin conditions and cancers with regular sunscreen use.5,14,15 In children aged <6 months, the American Academy of Pediatrics recommends avoidance of sun exposure and use of adequate clothing. If this is not possible, parents can apply a small amount of a broad-spectrum, water-resistant sunscreen with an SPF of at least 15 to small areas.16
Despite this knowledge, many do not adequately protect themselves from UV rays, especially teenagers and younger adults (18-29 years old).1,17-19 In one study evaluating 10,000 teenagers, 83% reported having at least one sunburn in one summer and 36% reported having three or more; only a third of respondents reported using sunscreen before their most serious burn.18
Not only are people not using sunscreen, but those who do are not applying it properly. Many apply sunscreen too thinly and infrequently.17 This may be due to the fact that most individuals do not understand sunscreen label terminology and/or hold misconceptions about important facts regarding sunscreen use.20,21 One ounce of sunscreen, or enough to fill a shot glass, is needed to adequately cover the exposed areas of the body; most people apply only 25% to 50% of this amount.11,17 The amount should be adjusted according to body size. It should be applied liberally and uniformly. Ensure patients are also applying sunscreen to their face, scalp (if they do not have much hair), lips, ears, nose, neck, backs of hands, and tops of the feet. Sunscreen should be applied at least 15 minutes prior to sun exposure, allowing time for the sunscreen to bind to the skin. To remain effective, sunscreen needs to be reapplied often, ideally every 2 hours or after swimming or heavy perspiration.
In addition to sunscreen use, it is important to remind patients to use other protective measures (see Patient Information).
Conclusion
The use of sunscreens is an important component to sun protection. Regular and appropriate use is associated with a decreased risk of various skin complications and cancers as a result of UV radiation exposure. Sun protection needs to begin at an early age; approximately 25% of lifetime sun exposure occurs before the age of 18 years.6 Pharmacists need to continue to educate patients regarding appropriate use of sunscreen, emphasizing the proper amount and need for frequent reapplication. In addition, patients need to be reminded not to solely rely on the use of sunscreen. Other sun protective measures are needed to provide maximum protection.
PATIENT INFORMATION
What Is Sunscreen?
Sunscreens are products that, once applied, absorb, scatter, and/or reflect UV radiation to help prevent damage from the sun’s harmful UV rays.
Who Needs Sunscreen?
All individuals over 6 months of age, even those who only work indoors, should use sunscreen on a daily basis. Infants under 6 months of age should avoid sun exposure; provide them with shade and protective clothing when exposed to sunlight. Their skin is highly sensitive to sunlight and the chemicals found in sunscreens.
What Is SPF?
SPF is also known as sun protection factor. This is a measure of how effective a sunscreen is at preventing sunburn. In general, the higher the number, the better the protection. However, there is no proof to show that products with an SPF >50 are any better.
What Type of Sunscreen Should I Use?
Always select a sunscreen that is broad spectrum and water resistant, with a minimum of SPF 30.
How Much Sunscreen Should I Use?
• Apply at least 1 ounce (or enough to fill a shot glass) of sunscreen on a daily basis, 15 to 30 minutes prior to exposure to sunlight.
• Reapply the sunscreen every 2 hours, or sooner if you have been swimming or sweating. It is better to apply too much sunscreen rather than to apply too little.
• Remember to apply sunscreen to your lips—use a lip balm with at least an SPF 30. Also remember to apply sunscreen to the face, scalp (if you do not have very much hair), ears, nose, neck, backs of hands, and tops of feet.
How Should I Store My Sunscreen?
Sunscreen should be kept in a cool, dry place. It keeps its original strength for approximately 3 years, but improper storage may spoil the product. If you notice any changes in its color and consistency, or if it is past the expiration date, discard the sunscreen.
How Else Can I Protect Myself From the Sun?
• Minimize sun exposure between the hours of 10 am and 4 pm. This is when the sun’s rays are the strongest.
• Wear sun protective clothing, including wide-brimmed hats and UV-blocking sunglasses.
• Use caution around water, sand, and snow. These surfaces can reflect UV rays.
• Do not use tanning beds.
Do Those With Dark Skin Need to Use Sunscreen?
People of all skin types need to be careful with sunlight exposure because of the risk of both eye and skin damage. Those with darker complexions may tolerate higher levels of UV rays without getting burned, but this does not mean that they should not use sunscreen. The risk of skin cancer still exists!
REFERENCES
1. Centers for Disease Control and Prevention (CDC). Sunburn and sun protective behaviors among adults aged 18-29 years—United States, 2000-2010. MMWR Morb Mortal Wkly Rep. 2012;61(18):317-322.
2. CDC. Sunburn prevalence among adults—United States, 1999, 2003, and 2004. MMWR Morb Mortal Wkly Rep. 2007;56(21):524-528.
3. Wu S, Han J, Laden F, Qureshi AA. Long-term ultraviolet flux, other potential risk factors, and skin cancer risk: a cohort study. Cancer Epidemiol Biomarkers Prev. 2014;23(6):1080-1089.
4. Holman DM, Berkowitz Z, Guy GP, et al. The association between demographic and behavioral characteristics and sunburn among U.S. adults—National Health Interview Survey, 2010. Prev Med. 2014;63:6-12.
5. Narayanan DL, Saladi RN, Fox JL. Ultraviolet radiation and skin cancer. Int J Dermatol. 2010;49(9):978-986.
6. Balk SJ; Council on Environmental Health; Section on Dermatology. Ultraviolet radiation: a hazard to children and adolescents. Pediatrics. 2011;127(3):e791-e817.
7. Jou PC, Feldman RJ, Tomecki KJ. UV protection and sunscreens: what to tell patients. Cleve Clin J Med. 2012;79(6):427-436.
8. FDA. Questions and Answers: FDA announces new requirements for over-the-counter (OTC) sunscreen products marketed in the U.S. June 23, 2011. www.fda.gov/Drugs/ResourcesForYou/Consumers/BuyingUsingMedicineSafely/UnderstandingOver-the-CounterMedicines/ucm258468.htm. Accessed June 6, 2016.
9. FDA. Sunburn protection factor (SPF). www.fda.gov/aboutfda/centersoffices/officeofmedicalproductsandtobacco/cder/ucm106351.htm. Accessed June 6, 2016.
10. Oaklander M. This is the only sunscreen article you need to read. Time. June 17, 2015. http://time.com/3924609/sunscreen-spf-uva-uvb/. Accessed June 6, 2016.
11. American Academy of Dermatology. Sunscreen FAQs. www.aad.org/media/stats/prevention-and-care/sunscreen-faqs. Accessed June 6, 2016.
12. FDA. Labeling and effectiveness testing: sunscreen drug products for over-the-counter human use—small entity compliance guide. December 2012. www.fda.gov/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/ucm330694.htm. Accessed June 6, 2016.
13. Sambandan DR, Ratner D. Sunscreens: an overview and update. J Am Acad Dermatol. 2011;64(4):748-758.
14. Lautenschlager S, Wulf HC, Pittelkow MR. Photoprotection. Lancet. 2007;370(9586):528-537.
15. Green AC, Williams GM, Logan V, Strutton GM. Reduced melanoma after regular sunscreen use: randomized trial follow-up. J Clin Oncol. 2011;29(3):257-263.
16. American Academy of Pediatrics. Sun and water safety tips. May 3, 2016. www.aap.org/en-us/about-the-aap/aap-press-room/news-features-and-safety-tips/pages/sun-and-water-safety-tips.aspx. Accessed June 6, 2016.
17. Neale R, Williams G, Green A. Application patterns among participants randomized to daily sunscreen use in a skin cancer prevention trial. Arch Dermatol. 2002;138(10):1319-1325.
18. Geller AC, Oliveria SA, Bishop M, et al. Study of health outcomes in school children: key challenges and lessons learned from the Framingham Schools’ Natural History of Nevi Study. J Sch Health. 2007;77(6):312-318.
19. Buller DB, Cokkinides V, Hall HI, et al. Prevalence of sunburn, sun protection, and indoor tanning behaviors among Americans: review from national surveys and case studies of 3 states. J Am Acad Dermatol. 2011;65(5):S114.e1-S114.e11.
20. Wang SQ, Dusza SW. Assessment of sunscreen knowledge: a pilot survey. Br J Dermatol. 2009;161(suppl 3):28-32.
21. Kong BY, Sheu SL, Kundu RV. Assessment of consumer knowledge of new sunscreen labels. JAMA Dermatol. 2015;151(9):1028-1030.
22. FDA. Code of Federal Regulations Title 21. Part 352. Sunscreen drug products for over-the-counter human use. April 1, 2015. www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfCFR/CFRSearch.cfm?CFRPart=352&showFR=1. Accessed June 6, 2016.
23. Baron ED, Kirkland EB, Domingo DS. Advances in photoprotection. Dermatol Nurs. 2008;20(4):265-273.
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