Bogleech.com's 2016 Horror Write-off:
'Ere we are at the habitat o' the dreaded Paradox Wraith! Supposedly, their venom makes anyone they bite get older AND younger at the same time, both at an extremely fast rate; that is to say, after a few hours, they either die of old age or revert to a fetus and disappear. This process is called "Time blight" and is said to be excruciatingly painful as the victims body is ripped apart through time. There is no known antidote, but luckily nobody's ACTUALLY known to have been bitten by the things... which makes it a little weird that we know what happens. I think we figured it out by analyzing the fangs and venom-sacks of a deceased specimen, or something like that. Either way, they are something you do NOT want biting you!
Crikey! There's a paradox wraith now! Oh, she's a beaut; I don't think she's spotted m- ARGH! Well, she spotted me alright. It looks like I'm done for; the good news is I'm in good enough shape that I'll last a few days before the accelerated aging gets me, and I'm old enough that I won't revert to nonexistence for another day or so, either. Just take me to the research 'ospital so they can study the effects it has on my body. Guys? GUYS?
Oh, I see. THAT's why there aren't any reported cases. It doesn't just make you get younger and older at the same time. It also takes you through time in a rather different direction.