US Pharm. 2022;47(8):33-36.

ABSTRACT: Sunburns are associated with long-lasting damage to the skin from insufficient protection. Repeated sunburn occurrences are associated with skin cancer, one of the most common cancers worldwide. Fortunately, skin cancer is preventable with appropriate protection from the sun’s harmful ultraviolet rays. As the most accessible healthcare professionals, pharmacists have the opportunity to educate individual patients and communities about the dangers of sunburn and the modalities available to appropriately protect the skin. Key strategies involve identifying the patient’s Fitzpatrick skin phototype, personalizing the selection of sunscreen based on sun protection factor number, and appropriately managing sunburns.

Many people perceive sunburn as a painful inconvenience that generally resolves within a week with appropriate management. However, it is important for all individuals to consider not only the short-term effects but also the long-lasting damage that can result from insufficient protection against the sun’s powerful ultraviolet (UV) rays. Sunburns, particularly with repeated occurrences, are the leading cause of skin cancer, which is the most common cancer in the United States and worldwide.1 One in every five Americans will develop skin cancer by age 70 years, and approximately 9,500 Americans are diagnosed with skin cancer each day.2 Dispelling common misconceptions about sunburn and its risks can substantially help reduce the occurrence of this highly preventable form of cancer.2 Therefore, it is important for pharmacists to educate patients about the risks of sunburn and the use of sunscreen, as well as to assist in product selection based on the patient’s specific needs.

What Is Sunburn?

Sunburn is a radiation burn of the skin that is caused by increased exposure to UV rays emitted by the sun or by indoor tanning beds.3 This exposure prompts the cells located in the top layer of the skin to produce melanin and tan the skin, a protective mechanism for shielding the skin from the damaging UV radiation.3,4 Each occurrence of sunburn is associated with skin damage by both UV type A (UVA) and UV type B (UVB) rays.5 UVA rays break down the collagen of the skin and damage the sites where new skin cells are generated, hastening visible aging and wrinkles.6 UVB rays result in the tanned look that is also a sign of sunburn and DNA damage.7 Upon clinical presentation, the affected area will generally be erythematous and painful in proportion to the extent of the sun exposure.8 The full effect of a sunburn on the skin may not manifest until 24 hours or longer following sun exposure, with most individuals experiencing worse pain 6 to 48 hours after exposure.9 The signs and symptoms of sunburn are usually temporary, but the skin-cell DNA can be permanently damaged, with possible long-term sequelae including skin cancer and early aging of the skin.10

Types of Burns

Superficial burns (i.e., first-degree burns) are relatively mild and affect only the outer layer of the skin.11 With this type of burn, the patient experiences redness, discomfort, and possibly mild swelling without blisters, making self-treatment an option.12 Most sunburns are first-degree burns. Second-degree burns, which are commonly caused by hot surfaces, hot liquids, or flames, are typically extremely painful, red, blistered, and moist, and the burned area blanches when touched.12 Third-degree burns, which are usually caused by flames, hot liquids, or superheated gases, extend through the epidermis and dermis into the subcutaneous fat (or deeper).12,13 The pain associated with third-degree burns is limited, the affected area may appear white or brown and feel firm, and upon palpation there is often no notable return of color to the region.13 Sunburn rarely results in a third-degree burn.13

Risk Factors for Sunburn

Risk factors for sunburn include the amount of time that the skin is exposed to UV rays, the time of day of sun exposure, the degree of ozone depletion, medication exposure, and skin phototype.8 Additionally, tanning beds increase the risk of sunburn and accelerate the aging process.7 Agents that increase the risk of sunburn include tetracyclines, thiazides, sulfonamides, St. John’s wort, and other photosensitizing medications.8 The Fitzpatrick skin phototype classification, which is based on the amount of melanin in the skin, may be helpful for determining a patient’s likelihood of sunburn in response to UV radiation exposure.8 The Fitzpatrick skin phototypes are as follows8,14:
• Type I: pale white skin, burns easily, does not tan
• Type II: white skin, burns easily, tans with difficulty
• Type III: white skin, may burn but tans easily
• Type IV: light brown/olive skin, hardly burns, tans easily
• Type V: brown skin, usually does not burn, tans easily
• Type VI: black skin, very unlikely to burn, becomes deeply pigmented with UV radiation exposure

Patients with phototypes I, II, or III are more susceptible to sunburn, as their skin has less melanin to block the UV rays. These patients need more protection from the sun.8,14

Misconceptions About Deeper Complexions

Although lighter skin types are more susceptible to sunburn, deeper skin types also require protection from the sun. Skin cancer can occur in persons with deeper complexions—although it is uncommon—and can be deadly if diagnosis is delayed.15 Mortality rates in patients with deeper skin types are substantially higher than in patients with lighter skin types, and this is often a result of delayed detection and treatment.15 This may be related to issues of health equity and the lack of clinician training in the diagnosis of skin conditions in patients with deeper skin tones.16 Also, patients with deeper skin tones may believe that melanin is an absolute protectant against skin cancer; this belief results in a lower perceived skin cancer risk, which may lead to poor health outcomes.15

Skin Cancer

The three main types of skin cancer resulting from sunburn are basal cell carcinoma, squamous cell carcinoma, and melanoma.17 Basal cell and squamous cell carcinomas (also known as nonmelanoma skin cancers) are less-serious types of skin cancer that account for the most commonly diagnosed malignancies in the U.S.17 Melanoma, which is composed of abnormal skin-pigment cells called melanocytes, is the most potentially fatal form of skin cancer.18 Left untreated, melanoma can metastasize, leading to challenges in disease treatment and control.19 However, when detected early, melanoma has a 5-year survival rate of about 99%.20

Sunscreen

Sunscreen is a sun protectant that is helpful in preventing sunburn and reducing the risk of skin cancer.21 The two main categories of sunscreens are based on their mechanism of action: chemical-based (organic) and mineral-based (inorganic).22 Chemical sunscreens usually contain a combination of ingredients that provide coverage against both UVB and UVA radiation. Ingredients in this type of sunscreen absorb UV rays before they can damage the skin. Physical sunscreens (inorganic blockers) deflect UV rays and include ingredients such as titanium dioxide and zinc oxide.22

Who Should Use Sunscreen: All people older than 6 months of age should use sunscreen every day, whether they tan easily or not.23 As mentioned previously, every individual is susceptible to the effects of sun exposure regardless of skin tone and risk factors for sunburn.23 It is important to be aware that sunscreens are not recommended for infants younger than 6 months due to lack of data in infants and potential for product toxicity.23,24 The FDA recommends that infants be kept out of the sun between 10 AM and 2 PM and that they wear protective clothing if sun exposure is expected.24

Understanding Sunscreen Labels: Sunscreen selection is often based on the sun protection factor (SPF) number.25 This number indicates the approximate time until the sun’s UVB rays adversely affect the skin if the sunscreen is applied exactly as directed.23 SPF 30 or higher is necessary for extended outdoor activities, including running, hiking, and outdoor sports.22 SPF 15 is ideal for everyday exposure, such as dog-walking or driving to work. If the patient’s skin is lighter and more susceptible to burns, a product with an SPF of 30 to 50 may be beneficial.23,24

Broad-spectrum sunscreens are necessary for sufficient protection from both UVA and UVB rays.23 In the setting of intense exercise, swimming, or water-based activities, water-resistant and very-water-resistant sunscreens are the most protective. No sunscreen is completely waterproof, but those labeled “water resistant” have been tested and are effective for up to 40 minutes of swimming, whereas “very-water-resistant” sunscreens remain effective for up to 80 minutes in the water.23

Sunscreen Types and Application: Sunscreens are available OTC in many forms, including lotions, creams, sticks, gels, oils, butters, pastes, powders, and sprays.24 Importantly, spray sunscreens are generally not recommended, especially in children, due to the risk of inhalation and potential for toxicity.26 For all forms of sunscreen, it is recommended that a liberal uniform film be applied 15 minutes before sun exposure.23 For full broad-spectrum protection, 1 oz. (for reference, the amount in a full shot glass) must be applied. At a minimum, sunscreen should be applied to every part of the body that is exposed to the sun, including areas that are likely to be missed, such as the tops of the ears, back of the neck, and feet.23

Irritant contact dermatitis that develops following sunscreen use is the most common adverse effect.27 This condition may be due to fragrances, preservatives, or other chemicals present in the sunscreen formulation. Avobenzone and octocrylene, which are found in chemical sunscreens, can induce allergic reactions. Any new product should be tested on a small area of the skin for a day or two before it is applied widely.27 Titanium dioxide, found in inorganic sunscreens, is generally a safe option for individuals with sensitive skin.28

Other Prevention Strategies

Sun avoidance is not always feasible, so it is important to know methods for preventing sunburn. Full-length clothing and wide-brimmed hats are UV-protective, and sunglasses with UV protection are available.29 Clothing technology has led to the development of garments with additional sun protection known as ultraviolet protection factor (UPF).30 A UPF rating of 30 means that only one-thirtieth of UV radiation passes through the fabric. A rating over 25 is considered very good, and any rating over 40 is excellent.29

Sunburn Treatment

Treatment options for sunburn vary depending on the severity of the burn. See TABLE 1 for a summary of types of burns and their treatment.12,31-37

The Pharmacist’s Role

Pharmacists are the most accessible healthcare providers within the community.38 The prevalence of skin cancer is alarming, but pharmacists can play a key role in educating patients and communities. Pharmacists can evaluate patients’ needs based on risk factors including medication therapy; they can also encourage informed decisions, including strategies for the prevention and treatment of sunburns. Because of their knowledge of medications, pharmacists can be pivotal in reducing the number of cases of preventable sunburn and skin cancer.

Conclusion

Thorough education about sunburn and its risks is necessary for the prevention of both the short-term and long-term effects of sun damage. Patients may hold erroneous beliefs regarding their sunburn risk, which may result in overexposure to the sun’s UV rays. Because repeated sun exposure can lead to skin damage and skin cancer, it is important to educate patients on appropriate sun-protection strategies. Pharmacists are an important resource when it comes to sunburn, sunscreen, and skin cancer education.

REFERENCES

1. Linos E, Katz KA, Colditz GA. Skin cancer—the importance of prevention. JAMA Intern Med. 2016;176(10):1435-1436.
2. American Academy of Dermatology Association. Skin cancer. www.aad.org/media/stats-skin-cancer. Accessed May 15, 2021.
3. Amaro-Ortiz A, Vanover JC, Scott TL, D’Orazio JA. Pharmacologic induction of epidermal melanin and protection against sunburn in a humanized mouse model. J Vis Exp. 2013;79:50670.
4. Le Clair MZ, Cockburn MG. Tanning bed use and melanoma: establishing risk and improving prevention interventions. Prev Med Rep. 2016;3:139-144.
5. Lopes DM, McMahon SB. Ultraviolet radiation on the skin: a painful experience? CNS Neurosci Ther. 2015;22(2):118-126.
6. University of Rochester Medical Center Health Encyclopedia. Ultraviolet (UV) radiation and your health. www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=85&contentid=P01359. Accessed May 15, 2021.
7. D’Orazio J, Jarrett S, Amaro-Ortiz A, Scott T. UV radiation and the skin. Int J Mol Sci. 2013;14(6):12222-12248.
8. Guerra KC, Crane JS. Sunburn. In: StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing; 2022 Jan-.
9. National Institute for Occupational Safety and Health. Sun exposure—sunburn. www.cdc.gov/niosh/topics/sunexposure/sunburn.html. Accessed May 15, 2021.
10. Del Bino S, Duval C, Bernerd F. Clinical and biological characterization of skin pigmentation diversity and its consequences on UV impact. Int J Mol Sci. 2018;19(9):2668.
11. Shpichka A, Butnaru D, Bezrukov EA, et al. Skin tissue regeneration for burn injury. Stem Cell Res Ther. 2019;10(1):94.
12. Schaefer TJ, Szymanski KD. Burn evaluation and management. In: StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing; 2022 Jan-.
13. Levi B, Wang S. Burns. In: Kang S, Amagai M, Bruckner AL, et al, eds. Fitzpatrick’s Dermatology. 9th ed. New York, NY: McGraw-Hill Education; 2019:1679-1692.
14. Oakley A. Fitzpatrick skin phototype. DermNet NZ. https://dermnetnz.org/topics/skin-phototype/. Accessed April 19, 2021.
15. Buchanan Lunsford N, Berktold J, Holman DM, et al. Skin cancer knowledge, awareness, beliefs and preventive behaviors among black and hispanic men and women. Prev Med Rep. 2018;12:203-209.
16. Buster KJ, Stevens EI, Elmets CA. Dermatologic health disparities. Dermatol Clin. 2012;30(1):53-59.
17. Wu S, Cho E, Li W-Q, et al. History of severe sunburn and risk of skin cancer among women and men in 2 prospective cohort studies. Am J Epidemiol. 2016;183(9):824-833.
18. Sample A, He YY. Mechanisms and prevention of UV-induced melanoma. Photodermatol Photoimmunol Photomed. 2018;34(1):13-24.
19. Damsky WE, Rosenbaum LE, Bosenberg M. Decoding melanoma metastasis. Cancers (Basel). 2010;3(1):126-163.
20. Skin Cancer Foundation. Melanoma overview. www.skincancer.org/skin-cancer-information/melanoma/. Accessed May 15, 2021.
21. Sander M, Sander M, Burbidge T, Beecker J. The efficacy and safety of sunscreen use for the prevention of skin cancer. CMAJ. 2020;192(50):E1802-E1808.
22. Gabros S, Nessel TA, Zito PM. Sunscreens and photoprotection. In: StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing; 2022 Jan-.
23. Skin Cancer Foundation. All about sunscreen. www.skincancer.org/skin-cancer-prevention/sun-protection/sunscreen/. Accessed April 25, 2021.
24. FDA. Sunscreen: how to help protect your skin from the sun. www.fda.gov/drugs/understanding-over-counter-medicines/sunscreen-how-help-protect-your-skin-sun. Accessed May 12, 2021.
25. Dale Wilson B, Moon S, Armstrong F. Comprehensive review of ultraviolet radiation and the current status on sunscreens. J Clin Aesthet Dermatol. 2012;5(9):18-23.
26. Law RM, Maibach HL. Skin care and minor dermatologic conditions. In: DiPiro JT, Yee GC, Posey M, et al, eds. Pharmacotherapy: A Pathophysiologic Approach. 11th ed. New York, NY: McGraw-Hill; 2020:37-38.
27. Keyes E, Werth VP, Brod B. Potential allergenicity of commonly sold high SPF broad spectrum sunscreens in the United States; from the perspective of patients with autoimmune skin disease. Int J Womens Dermatol. 2019;5(4):227-232.
28. Skocaj M, Filipic M, Petkovic J, Novak S. Titanium dioxide in our everyday life; is it safe? Radiol Oncol. 2011;45(4):227-247.
29. Guerra KC, Zafar N, Crane JS. Skin cancer prevention. In: StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing; 2022 Jan-.
30. Louris E, Sfiroera E, Priniotakis G, et al. Evaluating the ultraviolet protection factor (UPF) of various knit fabric structures. IOP Conf Ser Mater Sci Eng. 2018;459:012051.
31. Bernard DB. Minor burns, sunburn, and wounds. In: Krinsky DL, Ferreri SP, Hemstreet BA, et al, eds. Handbook of Nonprescription Drugs: An Interactive Approach to Self-Care. 19th ed. Washington, DC: American Pharmacists Association; 2018.
32. Simões D, Miguel SP, Ribeiro MP, et al. Recent advances on antimicrobial wound dressing: a review. Eur J Pharm Biopharm. 2018;127:130-141.
33. Waitzman AA, Neligan PC. How to manage burns in primary care. Can Fam Physician. 1993;39:2394-2400.
34. Schaefer TJ, Nunez Lopez O. Burn resuscitation and management. In: StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing; 2022 Jan-.
35. PCRM’s Nutrition Guide for Clinicians. Burns. https://nutritionguide.pcrm.org/nutritionguide/view/Nutrition_Guide_for_Clinicians/1342058/all/Burns?refer=true. Accessed May 25, 2021.
36. Roshni PR, Reghu R, Vijayan M, Krishnan P. Evaluation and management of sunburn. IJRPC. 2014;4(2):342-345.
37. American Academy of Dermatology. How to treat sunburn. www.aad.org/public/everyday-care/injured-skin/burns/treat-sunburn. Accessed June 30, 2022.
38. Manolakis PG, Skelton JB. Pharmacists’ contributions to primary care in the United States collaborating to address unmet patient care needs: the emerging role for pharmacists to address the shortage of primary care providers. Am J Pharm Educ. 2010;74(10):S7.

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