How Do You Know When a Sunburn is Dangerous [dermtv Epi #510]

Everyone knows that the sun causes premature photo aging, blotching, wrinkling, broken capillaries, and of course, skin cancer. A sunburn is your first warning sign that the sun is causing damage. And a sunburn can actually destroy your skin as you've seen when the damaged skin peels off after a red, burning sunburn. But what determines when that sunburn is actually dangerous? What in that sunburn causes the damage that actually starts your skin cancer? The answer is a little scary. Hello, I'm Dr. Neal Schultz [pause] And welcome to DermTV. UV energy is much more powerful than visible light. For the scientifically curious, as the wavelength of light decreases, it's energy increases. And UV has a shorter wavelength than visible light. UV energy is so strong that it actually can break and then more importantly, distort the chemical bonds that connect the building blocks of the skin's DNA. That causes the DNA chain to become misshaped. Internal control mechanisms which are in place to try to prevent cancer cause that cell, with its mutated misshapen DNA, to commit suicide, technically called apoptosis, or programmed cell death. This is what ultimately causes your skin to peel after your sunburn. But not all cells, whether in the skin or other organs, obey these rules. And despite the DNA damage resulting in DNA mutation, some cells survive because of modest DNA repair sufficient to allow it to continue to reproduce, but now with mutated DNA. These are the cells, these are your cells, that years later grow into your skin cancer. How do you know if your sunburn caused this to actually occur? Well, there's no sure-fire method, but one tell-tale sign is usually a burn that blisters. So the more often you get badly sunburned, the more apt you are to get skin cancer, especially melanoma, the skin cancer that kills 1 American every 55 minutes. Bottom line: I never tell anyone not to go out in the sun and have fun, but I tell everyone how to protect themselves while they're in the sun: Apply a sunscreen with an SPF of at least 15 to 30 with UVA protection before sun exposure and reapply immediately after swimming or sweating and every 2 to 3 hours. Have fun!