IntroductionSun emits ultraviolet light, also known as ultraviolet radiation. There are three types of ultraviolet radiation,
UV-C, UV-B and UV-A. UV-C does not impact the skin, and is effectively screened by the atmosphere. Even with depletion of ozone, UV-C does not have any impact on humans. UV-A is very harmful and penetrates not only the skin, but also the eyes. UV-A rays penetrate the skin the deepest. Approximately 90% of UV-B is absorbed by the epidermis, and approximately half of UV-A reaches the dermis and subcutaneous fat. UV-A rays are the primary offenders in sunburn. Sunburn accelerates the aging process, manifested by wrinkles and a pebble stone appearance of skin, which develops over time. It is also a culprit in the increased risk of cataracts and skin cancer. As per Dr. Auerbach, UV-B is 1,000 times more responsible for inducing redness of the skin than UV-A. UV-B has its own timeline, as opposed to UV-A, and onset is usually 2-4 hours after
exposure, peaking after 12-36 hours, and fading over 3 days. Please note: For those vacationing at high altitudes or climbing enthusiasts, it should be noted that for every 1,000 foot increase in altitude, the UV intensity increases by 10%. UV-A radiation does go through glass. Therefore, driving in your car does not afford you protection against sunburn. There are many contributing factors in getting a sunburn, which include time of exposure, skin type, and geographic location. As per Dr. Marilynne McKay, below are some general guidelines to consider:After 12 minutes of exposure, a perceptible sunburn may be apparent. After 30 minutes, vivid sunburn will be present. After 60 minutes, painful sunburn is apparent. After 120 minutes, blistering sunburn. Sun Protection Factor (SPF)What is the SPF value on
sunscreen? This is defined by a ratio of energy that is required to produce minimal redness of the skin penetrating the sunscreen, compared to the amount of energy required to produce the same reaction with the absence of sunscreen. This gives you some idea of how long you can remain in the sun before burning. An example as provided by Dr. McKay, if one would normally burn in 10 minutes without sunscreen, applying a 15 SPF would provide you approximately 150 minutes in the sun before burning, approximately 15 times the protection. A sunscreen of 15 SPF filters out about 90% of UV rays. It should be noted that filtration or protection of UV-A in sunscreen is only about 10% of the UV-B rating.It should be noted that these studies are carried out in a controlled environment, and factors such as altitude, skin type, wind, reflection of snow, sweating or toweling off of sunscreen are not taken into consideration. Important facts most individuals don’t know: Per Dr. Marilynne McKay:Sunscreen needs to be applied one half hour before exposure for full skin absorption. Waterproof type sunscreen should be applied at least once an hour before going out into the sun. Sweating, swimming, and exposure to rain decrease the effect of SPF. The FDA recommends reapplying sunscreen every 40-80 minutes. One ounce of sunscreen lasts no more than 4 days per person. SPF number does not apply to UV-A. So an SPF of 25 or an SPF of 30 with no UV-A screen will be less effective than a product with SPF that contains UV-A screen. Insect repellents containing Deet will decrease a product’s SPF by anywhere from 15-30%. Always protect your eyes with good quality sunglasses. The risk of cataracts needs to be underscored. Certain medications increase one’s risk of sunburn by increasing the photosensitivity of the skin. Caution should be exercised if taking the following medications, although the list is not complete: Antihistamines. Oral contraceptives. Estrogen. Anti-inflammatories. Ibuprofen. Phenothiazines. Certain antibiotics, specifically the sulfonamides. Diabetes medication. Certain diuretics. Anti-malarial medication. Tetracyclines such as Doxycycline. Some tricyclic antidepressants. Some deodorantsand soaps. Some herbal medication such as St. Johnswort can increase the risk of sunburn. .Sunburn TreatmentAfter sunburn has resulted, there is not much than can be done except make the patient more comfortable. Analgesics such as aspirin and Ibuprofen may help the inflammation. Topical steroids are of absolutely no help. Aloe gels can be helpful in relieving pain. Applying cool water is also very effective.Healthcare Provider- Medical Treatment
Survive Outdoors recognizes that when blistering occurs, there is much controversy in terms of removing the blisters or not in the outdoors, when far from treatment. It is advised to keep the blisters on. They will help keep the area clean. However, once reaching medical providers, this author has always debrided the blisters and applied Silvadene with very good outcome. Tapered doses of Prednisone are also effective in severe cases in decreasing inflammation. In severe forms, narcotic analgesics help to reduce the pain.