Galen has quite the talent for tongue-in-cheek humor: Galen’s Log: Use of Vancomycin in Loxosceles mersenius envenomation.
Despite intensifying research, Loxosceles mersenius remains an elusive species. Out of the 94% of patient reporting the spider bite, only 6 percent actually recall seeing a spider within a 48-36 hour window of noticing symptoms, and only a few samples have been submitted for research. Detailed testing revealed the specimens to be mashed remains of garden variety house spiders, while another umbillical specimen turned out to be a benign (though albiet frightening appearing) collection of dark cotton/polyester blend fibers.
Though I don’t want to spoil the ending, not every human with an abscess has theirs caused by a spider bite.