Inflammatory Skin and the Importance of Sun Protection

Everyone needs sun protection, but if you’re struggling to control certain skin conditions, it’s particularly important to find the right kind. The primary stressor for inflammation-based conditions like photoaging, rosacea and hyperpigmentation is—you guessed it—sun exposure. Here’s are the most common sun traps and how to avoid them.

Sun Trap #1: Photoaging and UV exposure

UVB—Burning rays which penetrate to the epidermis cause redness and itching, damage DNA and are linked to squamous and basal cell carcinomas. At their peak between 10am to 4pm, UVB rays reflect off shiny surfaces, making snow, sand and water excellent sunburn accelerators.

UVA—Aging rays penetrate to the dermis and cause wrinkles by cross-linking collagen and elastin, and hyperpigmentation because they turn melanin darker. Present from sunup to sundown, they penetrate clouds and glass.

Tips

1. Always wear a zinc oxide-based sunscreen, SPF 30, rain or shine.
2. Be wary of chemical sunscreens offering UVA protection, as the problems they create can be worse than the cure. Avobenzone protects against longer wavelength UVA rays, up to 400 nm, but it degrades quickly in the presence of UV. It is usually stabilized with octocrylene, but octocrylene is a new, emerging photoallergen that can create photoallergic contact dermatitis in adults. Allergic adults are advised to stay away from sunscreen products containing octocrylene, benzophenone-3 and fragrances. Octinoxate is sometimes added to the mix because it provides good protection in the UVB range, but it also degrades avobenzone and limits stabilization of avobenzone by octocrylene (a good explanation of why can be found here). You’ll want to avoid octocrylene anyway because an allergy may develop. The safest—and easiest—path is to simply avoid sunscreen with the following chemicals: avobenzone, octocrylene, octinoxate, benzophenone-3 and fragrances. Instead, use zinc oxide—it protects up to and past the 400 nm range, and is very stable.
3. The standard sunscreen reapplication rule is every two hours. A little-known but true factoid is that this rule exists not because you sweat or wash it off after a certain amount of time, but because chemical sunscreens have a nasty habit of degrading in sunlight (because they work by absorbing UV energy) quickly. They then start to generate their own free radicals. If you are using a chemical sunscreen, be sure to follow the two-hour rule vigilantly, since you are reapplying throughout the day to protect yourself from the sun and from degraded sunscreen chemicals. A morning application of zinc oxide sunscreen SPF 30 will continue to protect all day under normal, everyday conditions. Reapply after a swimming or sweating, and if you are skiing, at altitude, at the beach, etc., reapply every two to three hours.

Sun Trap #2: Rosacea and UV exposure

Rosacea involves a complex interaction of different factors and pathways leading to a chronic inflammatory and vascular response. A major instigating factor is UVB/ UVA exposure.

UVB rays penetrate to the epidermis and increase secretion of two factors: vascular endothelial growth factor (VEGF) and fibroblast growth factor 2 (FGF2). These increase vascularization of the skin and cause swelling.

UVB triggers activation of vitamin D3, which directly induces the expression of cathelicidin. Cathelicidin is an antimicrobial peptide that, when processed by rosacea-type skins results in vasoactive and pro-inflammatory peptides and peptide fragments.

UVA and UVB—UV irradiation also produces reactive oxygen species (ROS), which cause vascular and dermal matrix damage by stimulating enzymes, which break down collagen in the dermal matrix. A damaged dermal matrix may permit leakage and accumulation of inflammatory mediators and prolonged retention of inflammatory cells.

Tips

Many people with rosacea simply do not tolerate sun very well at all and are advised to limit their sun exposure. However, because most of us like a little sun, these suggestions will help boost your tolerance.

1. Wearing a zinc oxide sunscreen is very important for rosacea-prone people. Because sun damage continues even after the sun is no longer working directly on your skin, and because zinc oxide is a wonderful anti-inflammatory, you may add another layer of zinc oxide sunscreen in the evening. Use it in addition to your regular nighttime routine.
2. Because vitamin D3 does stimulate cathelicidn expression—but you want vitamin D3—apply sunblock to areas where rosacea is a problem—namely, your face. You’ll get enough vitamin D3 synthesis by exposing the rest of your body. And don’t shower right away—vitamin D takes a while to synthesize from the oils on your skin.
3. Take antioxidant supplements daily, especially astaxanthin and lycopene. These antioxidants from the carotenoid family will increase your tolerance to the sun. Retinoids help with inflammation by reducing signals that trigger cathelicidin production. Use a retinol or retinoid product at night and be hypervigilant about sun protection if you do use a retinoid product.

Sun Trap #3: Hyperpigmentation and UV Exposure

UVB stimulates melanin biosynthesis.

UVA turns melanin darker.

Tips

1. Remember that UVA rays penetrate glass and clouds and are always present. Wear zinc oxide sunscreen every day, rain or shine.
2. If you are taking medications, check to see if photosensitization or hyperpigmentation are side effects.
3. Avoid skin-bleaching ingredients like benzoyl peroxide and hydroquinone. They are well-known photosensitizers and may increase your hyperpigmentation.
4. Avoid fragrances and essential oils that may cause photosensitivity: oil of bergamot, lemon, lemongrass, jasmine absolute and musk ambrette.
5. Don’t get too hot—heat stimulates melanin production, so if you exercise in the sun, be sure to take breaks to cool down.