What The Health?! Spider bite leaves child with gaping hole in leg

A live Brown Recluse Spider crawls in a dish at the Smithsonian Institution National Museum of Natural History, Wednesday, March 30, 2011. (AP Photo/Carolyn Kaster)

Can leftover spaghetti really kill you? Can you actually cough up a blood clot in the shape of your lung? In Yahoo Lifestyle Canada‘s newest series, What The Health?!, we ask doctors to weigh in on odd health news stories and set the record straight. Be sure to check back every Friday for the latest.

A nine-year-old boy in the U.K. has recovered from the kind of bug bite that’s the stuff of horror flicks: a gaping hole formed on his leg after what was suspected to be a visit from a spider.

According to South West News Service, Bobby Cleary initially experienced itchiness and swelling at the site of an apparent bite, which his mom, Emma Barnett, treated with antiseptic cream. A few days later, however, she got a call from the school saying that he was limping and that he wound was oozing.

It only got worse from there, with Cleary being having to be taken to the emergency room the next day. The wound turned into a one-inch-deep hole, and the boy needed an IV drip to flush out the poison.

Although the critter in question was never found or identified, it was assumed that the boy had been on the receiving end of a brown recluse spider’s unwanted attention.

One of the signs of this arachnid’s bite is an ulcer developing at the site of the bite, with the skin in the centre turning purple. Approximately 10 per cent of these bites can lead to ulcers or blisters so severe that medical attention is required.

Other symptoms include pain or redness, fever, chills, nausea, joint pain, weakness, and, in rare cases, seizures or coma.

Brown recluse spiders aren’t the only type of arachnid that can, in extreme cases, cause dreadful health effects.

The widely feared black widow is another. Females can bite when disturbed, releasing a protein venom—aka poison—that affects the nervous system.

Reactions can consist of pain, burning, swelling at the bite site. Some people experience sore and stiff muscles, difficulty breathing, sweating, abdominal pain, swollen eyelids, weakness, or tremors.

Sometimes, you can see two fang marks.

ALSO SEE: What The Health?! Were bees really living in a woman's eye? Canadian experts doubtful

There have been other reports of people who’ve wound up with dangerous, gaping holes on their extremities due to apparent spider bites. In 2017, a 21-year-old British man had to have surgery to remove an infected area of flesh.

Stories like these might make arachnophobes jump onto their couch at the very sight of something crawling along the floor, but such cases are exceedingly rare.

Arachnologist Catherine Scott, PhD candidate at the University of Toronto Scarborough, says that in North America, the only kind of spider bite known to result in tissue necrosis is that of the brown recluse. And, in great news for anyone in Canada who’s terrified of eight-legged creatures, brown recluse spiders do not occur here. They’re restricted to the central and southern United States.

The vast majority of recluse bites have minor symptoms and heal without any medical intervention, Scott says. She points out, too, that in Cleary’s case, a spider was never positively identified as the cause of the boy’s wound; she suspects it was ore likely an infection of an insect bite. He had a medical condition as a child that makes him more prone to infections sepsis.

“Unfortunately, medical professionals in this country often diagnose lesions as recluse bites even though patients never witnessed a spider biting them,” Scott says. “There is a long list of conditions that can be and often are misdiagnosed as recluse bites, including bacterial infections like flesh-eating disease and Lyme disease.

“These misdiagnoses and the fact that many pest control companies advertise services to control brown recluse infestations in Canada lead to the mistaken impression that this species occurs here,” she adds. “It does not.”

The only spiders that are considered medically significant in Canada are black widow spiders in the genus Latrodectus, Scott says.

ALSO SEE: What The Health?! Teen dies from rare brain infection

We have two species: the western black widow, which is found in B.C. and Alberta; and the northern widow, which lives in southern Ontario and Quebec.

“Although the venom of these spiders is neurotoxic and can make people very ill, they are extremely shy and secretive and hesitant to bite,” Scott says.

Another spider that Canadians may have heard is dangerous is the hobo, which is common in B.C. It is in fact harmless, but has garnered what Scott calls an undeserved reputation for being aggressive and causing symptoms like those of brown recluse spiders.

“There is no evidence for these claims,” Scott says. “I've spent a lot of time handling these spiders for my work, and it would be difficult to be bitten by one because their main response to humans is to run away as fast as possible.”

More good news: In general, spiders have no reason to bite humans, Scott says. And, unless someone has an underlying health condition, or a bite of any kind becomes infected, spiders in Canada do not pose health risks to humans.

Unlike mosquitoes, ticks, bedbugs, and other blood-feeding arthropods, our blood is not on the menu for spiders.

“In Canada, the only reason a spider would bite is for defense, if it is crushed between the skin and clothes or shoes, for example,” Scott says. “Other than black widow spiders, the worst symptoms one can exp”ect from a spider bite in Canada is pain and swelling similar to a bee or wasp sting.

“When people wake up with mystery bites, they are almost certainly not spider bites, particularly if there are multiple bites,” she adds. “Spiders who are feeling threatened and defensive are extremely unlikely to stick around and bite a second time. Spiders do not bite humans in their sleep like many insects do, because spiders do not feed on our blood.”

ALSO SEE: What The Health?! Mom with rare double uterus gives birth twice in one month — but how?

Bites can happen if a spider has made its home in shoes or clothing and you disturb or scare it while grabbing the clothes.

If you store boots and other clothing in sheds, garages, or basements where there are a lot of spiders, Scott suggests shaking things out before putting them on. Avoid grabbing and crushing spiders with your bare hands, and look before you reach into dark corners where a spider might have made a web.

If you think you’ve been bitten by a spider, it’s best to capture it or collect its body if it has been crushed so that it can be identified by an expert.

First aid includes cleaning the area with soap and water and applying an antibiotic ointment. You can also put the RICE acronym into effect. It stands for: rest, ice (to reduce pain and swelling), compression, and elevation (of the area of the body affected).

“If you suspect that the spider is a black widow, you should absolutely see your doctor, and bring the spider with you,” Scott says. “Linking the spider to the bite is critical for appropriate treatment.”

“If the symptoms include a bulls-eye rash medical attention is certainly warranted, because this is a symptom of Lyme disease,” she adds.

Scott reminds that spiders are more helpful to humans than they are harmful. “If you have them in your home, they are biting and eating insects, not you,” she says.

Let us know what you think by commenting below and tweeting @YahooStyleCA! Follow us on Twitter and Instagram.

Check out Yahoo Canada's podcast, Make It Reign — our hot takes on all things royals in a non-stuffy way — on Apple Podcasts and Google Podcasts.