Sense of Impending Doom

My sister and her family came over today. My little nephew had a bunch of bites on his back, and this became a topic of discussion for the night, wondering what bit him, when he got it, why it didn't get his brothers. So, being the uber-nerd I am, I decided to google it, and i'm going through pages and pages of bug bites and allergic reactions... and its the usual things,
redness...

...

...itchy skin, blotchy rash, swelling.... a sense of impending doom...

Wait. What? A sense of impending doom?!? What the H kind of bug bite has a reaction that causes a SENSE OF IMPENDING DOOM? I'm never friggin going outside ever again! Are you serious, if something weird bites you in the woods and you go see a doctor about it, he takes a look- "Oh yeah, there's a little redness, some swelling, is it itchy? ...oh yeah, ok, um have you felt any... impending doom?" .....Riiiiiight.