Continuing Education Activity

Photoprotection, including sunscreens, clothing, hats, makeup, sunglasses, and windshields, is essential for reducing skin damage and skin cancers caused by UV radiation. The damaging effects of UV radiation include photoaging and photocarcinogenesis. Photoaging can manifest as sagging and wrinkling, whereas photocarcinogenesis damages cells and DNA.

This activity outlines the indications, mechanism of action, and methods of administration for effective photoprotection. In addition, it reviews important adverse effects, contraindications, monitoring, and toxicology. Understanding the pharmacology of sunscreens and photoprotective agents enables healthcare professionals to effectively tailor sun protection strategies to individual patient needs. This activity is designed to provide essential knowledge and practical tools for the optimal use of sunscreens and other photoprotective agents. The activity aims to deliver evidence-based guidance to improve patient care and outcomes, focusing on strategies to minimize adverse reactions while maximizing the effectiveness of photoprotection. This activity equips healthcare professionals with the knowledge to provide safe, effective, and individualized sun protection care.

Objectives:

• Identify the mechanism of action of various classes of UV-blocking agents.

• Evaluate the benefits of sunscreens and photoprotection to block UV rays.

• Assess the adverse events associated with various sun-blocking products.

• Implement effective collaboration and communication among interprofessional team members to improve the outcomes and treatment efficacy for patients who may benefit from sunscreens and photoprotective agents.

Indications

Photoprotection is essential for reducing skin damage and skin cancers caused by UV radiation.[1][2] Photoprotection includes sunscreens, clothing, hats, makeup, sunglasses, and windshields.[3] The damaging effects of UV radiation include photoaging and photocarcinogenesis. Photoaging can manifest as sagging and wrinkling, whereas photocarcinogenesis is due to the damage of cells and DNA. Recurrent and severe sunburns are a risk factor for nonmelanoma skin cancer.[2]

Food and Drug Administration–Approved Indications

The Food and Drug Administration (FDA) classifies sunscreen as an over-the-counter medication. Currently, 16 UV filters—14 organic filters and 2 inorganic filters—including zinc oxide and titanium dioxide, are approved. The FDA has updated its guidelines on broad-spectrum sunscreen use, emphasizing UVA and UVB coverage, water resistance to indicate the duration of effectiveness, and sun protection factor (SPF). SPF-15 or higher is the recommended blocking strength, and manufacturers can label it as reducing the risk of skin cancer and early skin aging.[4] 

Off-Label Uses

The American Association for the Study of Liver Diseases guidelines for pediatric patients after liver transplantation recommend that clinicians should advise the use of protective clothing, sunscreen, and periodic screening for skin lesions.[5] Porphyria cutanea tarda is caused by decreased uroporphyrinogen decarboxylase activity, accumulating porphyrins in the liver and skin. Sun exposure activates these porphyrins, causing oxidative damage and skin blistering, especially in sun-exposed areas. Clinical features include chronic bullous lesions and blistering. Photoprotection and low-dose 4-aminoquinolines are key treatments.[6][7] According to a systematic review, sunscreen is an excellent preventative measure for post-inflammatory hyperpigmentation.[8] The FDA has also approved 2 inorganic filters, zinc oxide and titanium dioxide, which block UVA and UVB transmission.[9] The American Society of Clinical Oncology (ASCO) highlights the essential role of sun protection in preventing skin cancer, promoting broad-spectrum sunscreen and protective clothing. The ASCO advocates for public education on sunscreen application and urges consistent skin cancer prevention practices, including regular sunscreen use and the adoption of sun-protective behaviors.[10] The American Academy of Dermatology (AAD) suggests sunscreens with an SPF-30 or higher, water resistant with a broad spectrum, and sun-protective clothing and covering.[11] In addition, the AAD advises UV protection for patients with actinic keratosis.[12] For patients with a history of basal cell carcinoma, the AAD advises to practice sun protection and avoid sun exposure and tanning booths. Broad-spectrum chemical and physical sunscreens reduce UV light exposure when applied correctly. Routine sunscreen use and other protective measures are recommended.[13] Similarly, for patients with a history of cutaneous squamous cell carcinoma, the AAD highlights the importance of sun protection and avoiding direct sunlight. Broad-spectrum chemical and physical sunscreens are proven to decrease UV light exposure when applied correctly. Routine sunscreen use is recommended alongside other forms of photoprotection.[14] 

Sunscreen products should be avoided in infants younger than 6 months due to the immaturity of their skin barrier. If sunscreen is necessary, it should be gentle and non-irritating to the skin and eyes with a low potential of causing sensitization.[15] Nonmelanoma skin cancers and melanoma are significantly influenced by prolonged and unprotected UV exposure. Photoprotection, including sunscreens, is a key preventive measure, although challenges such as low patient compliance and potential skin reactions remain.[16] A study assessed the safety, effectiveness, and role in preventing UV-induced skin damage, such as melanoma and squamous cell carcinoma. Inorganic sunscreens such as titanium dioxide and zinc oxide provide a physical barrier that blocks UV radiation and is generally well-tolerated with minimal adverse effects. Organic sunscreens, comprising avobenzone and octocrylene, give a superior skin feel and offer protection against UVA and UVB rays. Still, they require careful consideration due to their potential endocrine-disrupting effects, with oxybenzone being particularly harmful.[17] Sunscreen is recommended for patients with systemic lupus erythematosus, as photoprotection has been shown to decrease disease exacerbations and minimize skin damage caused by UV exposure.[18] According to the Kidney Disease: Improving Global Outcomes (KDIGO) 2024 guideline, broad-spectrum sunscreen is recommended for protection against UV light exposure in lupus nephritis.[19]

Mechanism of Action

UV radiation significantly impacts the skin, causing aging, sunburns, precancerous and cancerous lesions, and immunosuppression.[20] UV radiation has an immunosuppressive effect on the antigen-presenting cells within the epidermis and contributes to the likelihood of skin cancer.[4] There are 3 types of UV radiation—UVC, UVB, and UVA. The ozone layer absorbs 100% UVC, 90% UVB, and only a minimal amount of UVA. As a result, the depletion of the ozone layer increases UV transmission. UVA is associated with aging and pigmentation. This radiation penetrates deep into the skin layer and produces free radical oxygen species, indirectly damaging DNA. UVA increases the number of inflammatory cells in the dermis and decreases the number of antigen-presenting cells.[21] In contrast, UVB causes sunburn and DNA strand breaks, leading to pyrimidine dimer mutations linked to nonmelanoma skin cancers.[22] 

Photoprotection consists of both primary and secondary protective factors. The primary factors include sunscreens, which consist of physical barriers that reflect and scatter light and chemical barriers that absorb light. The secondary factors include antioxidants, osmolytes, and DNA repair enzymes, which help to limit skin damage by disturbing the photochemical cascade that occurs with UV sunlight.[20] 

Chemical sunscreens are known as organic sunscreens. The mechanism of action is based on their chemical structure involving an aromatic compound conjugated with a carbonyl group. This structure allows high-energy UV rays to be absorbed, causing the molecule to become excited. As the molecule returns to the ground state, it releases the lower energy of longer wavelengths. The specific range of wavelength a sunscreen absorbs varies. Chemical sunscreens consist of UVA and UVB blockers. UVB filters absorb the entire spectrum of UVB radiation (290-320 nm). In contrast, UVA filters do not cover the entire spectrum of UVA radiation. UVA radiation is divided into UVA I (340-400 nm) and UVA II (320-340nm). Broad-spectrum sunscreens absorb UV radiation from both the UVA and UVB portions.[23] A randomized controlled trial showed that daily sunscreen use reduced the rate of solar keratosis formation among adults in a subtropical environment. Participants who applied sunscreen daily had a 24% lower rate of solar keratosis development compared to those who used sunscreen at their discretion. However, beta-carotene supplementation (30 mg daily) did not affect the prevalence or development of solar keratosis. These findings suggest that consistent sunscreen application may effectively reduce solar keratosis and possibly skin cancer risk.[24] When incorporated into sunscreens, DNA repair enzymes such as photolyase and T4 endonuclease V show promise in enhancing DNA repair mechanisms and improving photoaging outcomes. However, further research is needed to confirm their efficacy.[25]

UVB Blockers

UVB blockers protect against short-wave ultraviolet radiation (290–320 nm), which is the primary cause of sunburn, DNA damage, and skin cancer.

• Aminobenzoates
• Cinnamates
• Salicylates
• Octocrylene
• Ensulizole
• Camphor derivatives

Aminobenzoates are the most potent UVB absorber but do not absorb UVA. The use of aminobenzoates has declined due to para-aminobenzoic acid (PABA) sensitivity. PABA is a very effective UVB filter; however, it was reportedly the most common photoallergen and contact allergen. For this reason, PABA is now rarely used in sunscreens. Padimate O is the most widely used PABA derivative, offering an effective UVB filter with a favorable safety profile.[3]

Cinnamates have replaced PABA as the next most potent UVB absorber, including octinoxate (OMC) and cinoxate.[20] OMC is the most commonly used UVB filter in the United States, but it is not as effective at absorbing UVB rays as padimate O. For this reason, other UVB absorbers are combined to increase the SPF. OMC is not photostable and degrades in the presence of sunlight after a short period. Cinnoxate is a less common choice.[3]

Salicylates are used in high concentrations as they are weak UVB absorbers. These chemicals are also used to increase the effect of other UVB filters. The FDA-listed salicylates include homosalate (HMS) and octisalate. Salicylates decrease the photodegradation of other UV filters, such as oxybenzone and avobenzone. A water-soluble salicylate is trolamine salicylate.[3]

Octocrylene is a highly safe chemical associated with a decreased likelihood of irritation, phototoxicity, and photoallergic potential.[26] When combined with other UV absorbers, it can increase the SPF formula.[20]

Ensulizole is a pure UVB filter and does nothing that affects UVA. This chemical is a water-soluble compound commonly used in cosmetics for a lighter, less oily feel.[20]

Camphor derivatives are not FDA-listed but are moderately effective UVB filters. Terephthalylidene dicamphor sulfonic acid is a camphor derivative that is also a broad UVA filter.[3] 

UVA Blockers

UVA blockers protect against long-wave ultraviolet radiation (320–400 nm), penetrating deeper into the skin than UVB and contributing to photoaging, pigmentation, and skin cancer.

• Benzophenones
• Anthranilates
• Avobenzone
• Ecamsule

Typical benzophenones primarily absorb UVB; however, oxybenzone is considered a broad-spectrum absorber as it can also absorb UVA II.[20] Oxybenzone is the most commonly used benzophenone.[3] However, it is the most likely sunscreen ingredient to induce contact or photo-contact dermatitis. Oxybenzone is not considered photostable, and although it is not scientifically proven yet, there is a concern about carcinogenic and endocrine adverse effects.[20] Other FDA-listed benzophenones include sulisobenzone and dioxybenzone.[3] 

Anthranilates are weak UVB and UVA filters and are less effective than benzophenones. As a result, clinicians rarely use them.[3]

Avobenzones are considered broad-spectrum and have high efficacy against UVA I (>380 nm); however, they are photo-unstable and lose from 50% to 90% of their particles after 1 hour of UV exposure. Reports indicate that avobenzones degrade the UV filter OMC. UV absorbers such as octocrylene, benzophenones, salicylates, camphor derivatives, and micronized zinc oxide or titanium dioxide are combined to increase photostability.[3]

Ecamsule contains terephthalylidene dicamphor sulfonic acid, a photostable water-resistant product with low systemic absorption. In animal studies, it has been shown to prevent UVA-induced photoaging.[3]

Broad-spectrum sunscreens include methylene bis-benzotriazolyl tetramethylbutylphenol (MBBT) and bis-ethylhexyloxyphenol methoxyphenyl triazine (BEMT). MBBT is advantageous due to its large molecular size, which decreases the likelihood of systemic absorption or endocrine effects. MBBT combines organic and inorganic filters, ultimately absorbing, scattering, and reflecting UV radiation. MBBT decreases UVA transmission more than UVB. BEMT is also photostable and does not interfere with the endocrine system.[20]

The mechanism of action of a physical sunscreen is based on the reflection and scattering of UV light in much the same way as clothing. The reflective properties determine the effectiveness of the sunscreens. These properties include the reflective index, the size of the particles, the film thickness, and the dispersion of the base—the higher the reflective index, the better the UV filter. Decreasing the size of the particles to a micronized form (10-50 nm) is more cosmetically appealing but leads to the protection of shorter wavelengths and increases the risk of systemic absorption.[23] A thick coating increases the degree of reflection but is cosmetically less appealing. Iron oxide can be an additive to increase absorption and improve UVA protection. Physical sunscreens consist of zinc oxide and titanium dioxide.[3]

Microfine zinc oxide protects against a broad spectrum of UVA radiation, including UVA 1 (340-400 nm). This sunscreen ingredient is highly photostable and does not react with other UV filters. Although it is more effective compared to titanium dioxide for UVA protection, it is less effective against UVB radiation.[3][20]

Microfine titanium dioxide protects against UVA 2 (315-340 nm) and UVB but does not protect against UVA 1, as does zinc oxide.[20] This sunscreen ingredient has a smaller particle size and higher refractive index compared to zinc oxide, causing it to appear white and cosmetically less appealing. Photochemical reactions cause sunscreen to become less effective compared to zinc oxide and titanium dioxide. For this reason, silica and dimethicone coat these particles, stabilizing these inorganic filters.[3]

As mentioned above, secondary photoprotection includes antioxidants, osmolytes, and DNA-repair enzymes, which help to limit skin damage by disturbing the photochemical cascade that occurs with UV sunlight. The mechanism of action of antioxidants is to reduce the reactive oxygen species (ROS) produced from UVA radiation. Naturally, these ROS become neutralized by antioxidants found naturally within the body, such as superoxide dismutase and catalase. These enzymes can become saturated with an overproduction of ROS, resulting in a deficiency of antioxidants and damage to proteins and DNA. Topical antioxidants function from within the cell to decrease the shortage of antioxidants and can remain active for several days after application.[27][20]

Many sunscreens include antioxidants such as vitamin C, vitamin E, silymarin, and green tea polyphenols. Vitamin C protects against UV damage, which results in sunburn and erythema.[20][28] Vitamin E has many protective actions, such as decreasing immunosuppression, erythema, photoaging, and photocarcinogenesis.[20][29][30][31] Silymarin, derived from milk thistle plants, helps prevent lipid and lipoprotein oxidation while acting as a scavenger of ROS. The topical application reduces UVB-induced sunburn cells and decreases the formation of UVB-induced pyrimidine dimers. In mice, it has been shown to reduce the amount of UVB-induced tumors.[32] Green tea polyphenols contain more potent antioxidants compared to vitamins C and E. These polyphenols are anti-inflammatory and anti-carcinogenic and function to scavenge singlet oxygen, superoxide radicals, hydroxyl radicals, peroxyl radicals, and hydrogen peroxide.[33]

Osmolytes are small molecules that stabilize cells in stressful conditions by regulating hydration. Taurine and ectoine are osmolytes that protect against many UV effects and are components in many sunscreens.[20][34][35]

Pharmacokinetics

The pharmacokinetics of sunscreen active ingredients involve their absorption into the systemic circulation after topical application, with varying plasma concentrations depending on the formulation. For example, avobenzone reached maximum plasma concentrations of 7.1 ng/mL in a lotion formulation. After absorption, these ingredients are metabolized in the liver. Some compounds, such as oxybenzone and trolamine, inhibit certain cytochrome enzymes, such as CYP2C9, and drug transporters, such as OAT3 and OCT2, at high concentrations. Excretion can occur through the renal route, suggesting systemic absorption. Although systemic absorption of sunscreen active ingredients occurs, their impact on drug metabolism and transport appears minimal.[36][37][38][39]

Administration

Sunscreen should be applied topically. Proper application is crucial for its effectiveness. A liberal, uniform film should be applied at least 15 minutes before sun exposure. The adequate amount to apply is 2 mg/cm², equivalent to 30 mL per body application. Sunscreen should be reapplied every 2 hours and after sweating or swimming to maintain protection.[2]

Clothing is a form of photoprotection, which can be measured using the UV protection factor (UPF).[20] This metric measures the transmission of UVA and UVB through a given fabric. Animal studies showed that a UPF of over 30 can protect against erythema and premalignant lesions. Whether the fabric is wet or dry may increase or decrease UPF based on the type of fabric. Light-colored fabrics have decreased UPF compared to dark-colored fabrics.[3] Overall, clothing provides balanced protection against UVA and UVB, and a loose-fitting colored fabric is the best form of photoprotection.[20]

Hats are a variable form of photoprotection dependent on the brim width, material, and weaving. A hat with a brim width of more than 7.5 cm has an SPF of 7 for the nose, 5 for the neck, 3 for the cheeks, and 2 for the chin. A hat with a brim width of 2.5 to 7.5 cm has an SPF of 3 for the nose, 2 for the neck and cheek, and 0 for the chin. A hat with a brim less than 2.5 cm has an SPF of 1.5 for the nose and a minimal amount for the chin and neck.[3]

Sunglasses are a form of photoprotection for the eyes. Sun exposure can result in many eye conditions, such as cataracts, directly resulting from sun exposure, specifically UVB radiation. Chronic exposure results in the formation of cataracts and eye cancer. Sunglasses should absorb 99% to 100% of the full UV spectrum. Contact lenses can also provide photoprotection for the ocular lens; however, they do not protect the anterior portion of the eye.[3] 

Car windshields offer UV protection. The Federal Motor Vehicle Safety Standard No. 205 mandates that the tinted glass in cars provide no less than 70% transmission of visible radiation. The windshields of cars contain zinc, chrome, nickel, and other metals that block UV radiation. The windshield of the vehicle is more photoprotective compared to the side window glass of the automobile.[3] A study evaluating two SPF-15 sunscreen formulations on vitamin D synthesis during a week-long sun holiday found that both formulations permitted significant increases in serum 25-hydroxyvitamin D3. The high-UVA protection formulation supported better vitamin D synthesis compared to the low-UVA one, as it transmitted more UVB rays. These findings suggest that sunscreens can prevent sunburn while enabling adequate vitamin D production, with high-UVA formulations providing optimal balance.[40]

Adverse Effects

Adverse effects of sunscreen primarily include 4 types of contact dermatitis—irritant, allergic, phototoxic, and photoallergic.[23] In Germany, a 15-year study involving patch and photo patch testing found that a nonimmune-based irritant response is the most common reaction to sunscreen.[2] Benzophenones and dibenzoylmethanes are the most common UV filters that cause adverse effects, with benzophenone-3 (BP-3) being the most common photoallergen. As BP-3 is a derivative of PABA, it is not used frequently in the United States.[2]  Some studies have associated sunscreen use with melanoma due to the users' false sense of security, which may increase the duration of the sun, resulting in UVA formation and malignant changes.[23] Phototoxic and allergic contact dermatitis are typically the results of UVA (320-400 nm) and visible light ranges (400-800 nm). UVA is capable of penetrating the reticular dermis and is the cause of most photosensitivity reactions.[41]

An American study revealed that UV filters are the most common cause of positive photopatch tests.[42] The risk factors for sunscreen allergy remain unclear but are more likely to include sex, a history of photodermatosis, application on damaged skin, outdoor occupations, and atopy. Although concerns once existed that regular sunscreen use could lead to vitamin D deficiency, research indicates that consistent application does not significantly affect vitamin D levels.[2]

The adverse effects of physical sunscreen arise from the use of nanoparticles, which have a more beneficial cosmetic effect. The larger surface area of nanoparticles can lead to enhanced catalytic reactions, increasing the production of free radicals and causing damage to DNA and proteins. These smaller particles can form complexes with the protein that act as haptens, inducing autoimmune conditions.[20][43]

Three observations led to the review of animal and human studies regarding the adverse effects of UV filters:

• An increase in sunscreen use
• An increase in the incidence of malignant melanoma
• An increase in experimental studies showing adverse endocrine effects of UV filters

In vivo and in vitro animal studies have shown multiple potential adverse effects of UV filters within sunscreen. These adverse effects include endocrine dysfunction of the reproductive and developmental systems. The UV filters of concern include BP-3, 4-methylbenzylidene camphor (4-MBC), and OMC. An anti-estrogenic effect was strongly associated with BP-3, 3-benzylidene camphor (3-BC), 4-MBC, and OMC. This finding was based on the uterine weight of immature rats. UV filters demonstrated the anti-estrogenic effect of HMS, OD-PABA, and PABA in yeast expressing the human estrogen receptor α. Exposure to UV filters, including 3-BC and 4-MBC, resulted in delayed male puberty and reduced prostate weight. The mechanism of action behind the reproductive toxicity may be due to alterations in proteins of the gene expression of estrogen receptor, androgen receptor, progesterone receptor, insulin-like growth factor I, complement proteins, nuclear receptor co-repressor, and steroid receptor coactivator 1 in the uterus and prostate. In a 90-day study on BP-3, fertility was affected in male mice. This finding was demonstrated by decreased sperm density in a dose-related manner following dermal exposure in mice and oral exposure in mice and rats.[42]

Experimental studies in humans have demonstrated an increased permeability of the UV filters BP-3, 4-MBC, and OMC. Levels were detectable in the plasma 1 to 2 hours after exposure. The study also demonstrated a difference in concentration based on gender. Male urine and plasma concentration samples were higher than female samples. A Swiss study of human breast milk revealed that 85% of the sample contained UV filters. Bisphenol and BP-3 share a similar chemical structure. Bisphenol can cross the blood-placenta barrier, suggesting that BP-3 may also cross the placenta. An increased concentration of BP-3 in a mother's urine was associated with decreased birth weight in girls and increased birth weight and head circumference in boys.[42] A study found that frequent sunscreen use was associated with a higher prevalence of antinuclear antibodies in adults aged 20 to 39, particularly in females and non-Hispanic Whites and Blacks. Further research is required to explore this potential relationship.[44] Regarding new dosage forms, spray sunscreens are subject to more rigorous testing due to concerns about inhalation risks and flammability. These formulations may not be suitable for children or patients with respiratory conditions.

Contraindications

Although photoprotection is recommended for all age groups, the 1999 FDA Sunscreen Final Monograph advised that parents of infants younger than 6 months should consult a clinician before using sunscreen in this age group. This recommendation is based on infants' underdeveloped metabolism and their inability to excrete chemicals absorbed from sunscreen. If sunscreen is necessary, it should only be used occasionally on areas of the body that are exposed to sunlight.[3] According to regulations, sunscreens should not be used on damaged or broken skin (U.S. Food and Drug Administration. Final Administrative Order OTC000006. Over-the-Counter Monograph M020: Sunscreen Drug Products for Over-the-Counter Human Use ).

Monitoring

The FDA classifies and regulates sunscreen as an over-the-counter medication. The efficacy of sunscreen is determined by UVB protection, which is measured by the SPF and substantivity. SPF is the ratio of the smallest dose of UVB radiation required to produce minimal erythema on sunscreen-protected skin compared to the necessary dose of UVB to produce the same amount of erythema on non-protected skin. SPF is a better predictor of protection against UVB, as it is 1000 times more erythemagenic compared to UVA. An SPF-15 can block 94% of UVB radiation, whereas an SPF-30 can block 97% of UVB radiation.[3] Substantivity is the ability of a sunscreen to withstand adverse conditions such as water and sweat. The FDA defines specific terms for labeling substantivity—water-resistant refers to a 40-minute time interval of maintained photoprotection with water immersion and moderate activity, whereas very water-resistant refers to effectiveness for 80 minutes. Both terms can qualify as sweat-resistant.[20] The Fitzpatrick phototype classification categorizes skin into 6 types based on its response to UV light, emphasizing how it tans or burns. Monitoring skin type and sunscreen effectiveness is essential for achieving proper photoprotection.[45]

Toxicity

For contact dermatitis, the first step is to avoid the causative agent. Patch testing can help identify the etiologic agent. The results of patch testing can be listed on the American Contact Dermatitis Society website, providing patients with a list of non-allergenic products that can be used. Treatment includes topical steroids for local reactions, whereas severe reactions require the use of systemic steroids. If oral steroids are ineffective, immunosuppressants such as oral cyclosporine, methotrexate, or mycophenolate mofetil may be considered. For mild-to-moderate dermatitis, calcineurin inhibitors, pimecrolimus, and tacrolimus are options.[23]

In cases of photoallergy and phototoxicity, UVA radiation is typically a requirement to trigger the reaction. The patient should avoid the etiologic agent, but if avoidance is not possible, the patient should avoid direct sunlight and tanning beds and wear protective clothing and non-allergenic sunscreen.[23]

Barrier creams and high-lipid moisturizers can help prevent and improve irritant contact dermatitis.[23] Recent studies on the systemic absorption of sunscreen ingredients oxybenzone (BP-3) and OMC indicate that elevated BP-3 levels show no adverse effects on fertility, hormone levels, or child development—however, associations with thyroid hormone, testosterone, kidney function, and pubertal timing warrant further investigation. Current evidence does not support a causal link between elevated BP-3 or OMC levels and adverse health outcomes; further research is required to clarify potential risks.[46]

Enhancing Healthcare Team Outcomes

An estimated 1 million new cases of nonmelanoma skin cancer occur every year. The numbers have increased significantly in the United States over the past 20 years. According to a study, most residents of the United States understand the role of sunscreen in protecting against UV rays but apply it inconsistently, with 11% not using it at all. Increasing sunscreen education, especially in schools, could help improve usage patterns. Individuals in the lowest income bracket may also benefit from targeted interventions to enhance sunscreen use application.[47] For most individuals, healthcare providers are not the primary source of information for sun protection measures. The media has a significantly influential role; however, there is little long-term behavioral change. These findings support the importance of engaging healthcare professionals to increase patient education regarding photoprotection and its role in preventing nonmelanoma skin cancer.[48] A study shows that digital interventions, especially those with advanced features, can enhance sun protection, including the use of sunscreen and behaviors related to skin cancer detection among young adults at moderate-to-high risk.[49]

The Coronavirus Aid, Relief, and Economic Security Act (CARES Act) significantly impacted the regulation of over-the-counter sunscreen products. Active ingredients such as zinc oxide and titanium dioxide are recognized as Generally Recognized As Safe and Effective (GRASE).[50] These ingredients provide broad-spectrum protection. Conversely, ingredients such as PABA and trolamine salicylate are excluded from the GRASE list due to concerns over their safety, such as the potential for allergic reactions and skin irritation. Similarly, ingredients such as oxybenzone and avobenzone should be cautiously used due to the potential for systemic absorption and possible endocrine-disrupting effects. The SPF of sunscreen products is tested to determine their effectiveness in preventing sunburn. The FDA employs controlled UV exposure and Minimal Erythema Dose (MED) measurements to establish the level of protection. To be considered effective, sunscreens must have an SPF of at least 2, with higher SPF values recommended for extended sun exposure. Broad-spectrum sunscreens, which protect against both UVA and UVB radiation, are required for products with an SPF of 15 or higher. The FDA also mandates water resistance labeling. Sunscreens should undergo testing to assess how long they remain effective during swimming or sweating. Sunscreens that pass these tests are labeled as water resistant (40 minutes) or water resistant (80 minutes). This labeling helps clinicians guide patients in selecting suitable products for outdoor or water-based activities.

The FDA has outlined stringent requirements for sunscreen labeling. All sunscreen products must clearly state the SPF value, indicate whether they provide broad-spectrum protection, and list the duration of their water resistance. These labeling requirements ensure that patients understand the level of protection they are receiving and enable clinicians to make informed recommendations. The FDA has also determined that sunscreen-insect repellent combinations are not GRASE, as the ingredients in these products may interact and reduce the effectiveness of either the sunscreen or the repellent. Clinicians must, therefore, recommend separate products for sun protection and insect repellent to ensure that patients receive optimal protection from both sunburn and insect bites.

The FDA's proposed maximum SPF value for labeled products is 60+, based on the understanding that higher SPF values provide only marginal additional protection beyond SPF 60. For clinicians and pharmacists, these regulatory changes emphasize the importance of recommending sunscreens that provide broad-spectrum protection, appropriate SPF, and water resistance, especially for patients at high risk of skin damage or skin cancer. Excluding certain ingredients from the GRASE list necessitates caution when recommending sunscreens containing potentially harmful compounds such as oxybenzone or PABA. Educating patients on how to read labels and select appropriate sunscreen products is essential for safeguarding long-term skin health. Pharmacists should guide patients in choosing the best formulation based on individual needs (U.S. Food and Drug Administration. Final Administrative Order OTC000006. Over-the-Counter Monograph M020: Sunscreen Drug Products for Over-the-Counter Human Use ) (U.S. Food And Drug Administration. Proposed Order (OTC000008): Amending Over-the-Counter (OTC) Monograph M020: Sunscreen Drug Products For OCT Human Use).

A coordinated interprofessional effort from the interprofessional healthcare team, including clinicians and pharmacists, is crucial in helping patients avoid UV exposure and protect their skin. As retail pharmacists are uniquely positioned where sun protection products are sold and can also see if the patient is taking any medications with potential phototoxicity, they can exert a significant influence in this regard. Nurses can also counsel patients, and all team members should be aware of patients with fair skin who present with significant or frequent burns or who have a high level of UV exposure because of work. Through collaborative efforts, the healthcare team can optimize patient outcomes while minimizing adverse effects.