Here's a shocker: doctors are not entomologists. If you were ever told (or just assumed) that a festering wound was a spider bite, but you never caught the spider in the act, there's a good chance your ailment was something else instead. Photo via VisualHunt.
It's not entirely your doctor's fault, either. A analysis published in Toxicon shows that the published medical studies about spider bites — in other words, the ones your doctor was relying on — often get it wrong. The authors concluded that 78 per cent of publications on spider bites are unreliable, because either nobody saw the spider bite the patient, or because the spider wasn't identified by an appropriate expert.
So what are those festering wounds, really? An awful lot of them are methicillin-resistant Staphylococcus aureus (MRSA) infections. A spider research group at the University of California Riverside has put together a list of non-spider-bite conditions that tend to get blamed on spiders.