I was bit by a brown recluse as a kid. The symptoms were nothing like this but it did create a large nasty looking hole in my calf that seemed to grow for a couple of weeks rotting the flesh. It was unpleasant but not all that painful considering.
In addition to the recluse bite, I have been stung by bees, wasps, jellyfish and a scorpion but the worst was from nothing less than a caterpillar. It happened twice... two different kinds of caterpillars (the first one I put my hand on climbing a tree, the second I actually picked up). It was not to the level described in the article, but some of the same type symptoms appeared. My arm ached with horrible muscle pains, I felt symptoms throughout my body and I felt extremely ill for a day or so. I was around 10 or 12 at the time, we had just moved to Florida and I was quite surprised to learn that some caterpillars stung. I don't live there anymore but am still extremely wary of caterpillars that have any fuzz or hair.