When I get sunburn it seems like it takes a long time before the suns damage appears on my skin. Sometimes I donít see it or feel it until later in the day. Why is that?
Whatís happening when the sun is on your skins is that its causing damage in your skin. The Ultra Violet radiation on from the sun is zooming into your skin cells and causing the DNA in your cells to be damaged. This is prompting a lot of emergency reactions to go on in your skin cells. They realise theyíre damaged and lots of gene expression and signalling pathways get switched on in response to this damage to either patch up the cells that have been damaged by the sun or to kill themselves to protect your body from this damage. This actually takes some time to get going.
At the same time, because youíve damaged your skin, thereís going to be some kind of immune response going on as well, your bodyís activating itself to the damage so this is why youíre going to go red, get inflammation, and in some really serious cases youíll get skin blistering and swelling but this does all take time. These are biological processes, the sensing of damage is quite quick but actually getting the response going might well take a couple of hours. Itís best not to get sunburnt if you want to reduce your risk of skin cancer.