Spiders are given an unjustly bad press as dangerous creepy-crawlies whose bite can kill you, say experts.
Wolf spiders have been blamed for flesh-eating skin lesions
Writing in the Lancet, an Australian and a US doctor say most spiders pose no threat to humans and are scapegoats for flesh-eating skin lesions.
Diagnosis of spider bites are based mainly on suspicion and fear, say Dr Geoff Isbister and Dr Richard Vetter.
Deadly bites and stings from scorpions, wasps and bees are far more common, they say.
Dr Isbister, clinical toxicologist and emergency physician at Newcastle Mater Misericordiae Hospital, said spiders were often wrongly blamed for medical disease.
"The current myth asserts many types of spider are responsible for necrotic ulcers. This is a perception of both patients and medical practitioners.
"Putting aside emotion and dislike for these creatures, and based on rational assessment of the risks, the fear or concern about spiders is unfounded.
"Diagnosis of a spider bite continues to be based mainly on suspicion and fear of spiders, and diagnosis of a chronic ulcer in stories of suspected spider bites causing devastating necrotic fasciitis (flesh-eating disease)," he said.
The wolf spider and the white-tail spider, common in Australia and also found in the US, have both been blamed for such ulcers.
But Dr Isbister said in the described cases, no spider had actually been seen biting the person and a presumption had been made because the spider was later found in the house or garden some days later.
He said the subsequent media attention lead to Australian and US doctors diagnosing a white-tail spider bite on the basis of the appearance of the skin lesion without good evidence.
Tests on these spiders have shown the venom did not cause fleshing-eating disease, or dermonecrosis, which is supported by cases where the person has seen the spider biting them and has had only minimal skin lesions.
Deaths from spider bites are also extremely rare.
Only 26 deaths from spiders have been recorded in Australia in the past century.
In comparison, there were 1,183 motor vehicle deaths in 2001 in Australia.
"Fear of cars is rare and there are few myths about the medical effects of car travel even though more deaths occur from motor vehicle accidents each year than from spider bites," said Dr Isbister.
Dr Richard Vetter, from the department of entomology at the University of California, said: "The worldwide medical community would do well to relegate spider bite to the bottom of the list of different diagnoses and consider the plethora of other conditions that manifest in dermonecrosis which have higher probability of occurrence."
Jan Becaloni, curator of arachnida and myriapoda for the Natural History Museum, said: "I think that spiders have got really bad press.
"It's amazing how many times you do see spider things making the headline news when it's really something very minor.
"Certainly in the UK, people get a bit frantic for no necessary reason at all because they see something they think is big and foreign when it's actually a common British species.
"In the UK, we do have a few spiders that are able to bite and some people might have a reaction, but it's really rare indeed and nobody dies from British spider bites at all," she said.