A group of scientists have figured out (at least in part) why overexposure to UV light makes our skin get sore, red and swollen.
It goes like this:
- You sit out in the sun too long. (As if you haven’t been told.)
- Inside your skin cells, that little RNA molecule is damaged by UV-B — and its shape gets altered.
- Damaged skin cells release altered pieces of RNA.
- The altered RNA can bind to a receptor in undamaged skin cells and immune cells called peripheral blood mononuclear cells.
- These cells, as a result, start pumping out chemicals called cytokines that induce inflammation.
- Redness and swelling follow.
That’s not the end of it, though. Even though there’s a short term ramp-up in immune activity during sunburn, later on the immune system is suppressed for a period of time.
Learn more: L.A. Times – Ow, sunburn: Scientists figure out what’s going on in our skin
