Sunburn is painful. What goes on in the skin when you get it, and could the cascade somehow be stopped? Should it be stopped?
A group of scientists have figured out (at least in part) why overexposure to UV light makes our skin get sore, red and swollen. Reporting in the journal Nature Medicine, they showed in a set of experiments that exposure to UV-B rays damages a tiny molecule inside skin cells -- a little piece of RNA with no known function. The damage alters that little RNA’s shape, and the sunburn cascade begins.
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 RNA, in its altered shape, 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.