30th January 23:32
Spiders 'scapegoats for diseases'
Spiders 'scapegoats for diseases' Spiders are given an unjustly bad
press as dangerous creepy-crawlies whose bite can kill you, say
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
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 and 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
"Putting aside emotion and dislike for these creatures, and based on
rational assessment of the risks, the fear or concern about spiders is
"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.
People get a bit frantic for no necessary reason at all Jan Becaloni,
curator of arachnida and myriapoda for the Natural History Museum
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
In comparison, there were 1,183 motor vehicle deaths in 2001 in
"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. Story from BBC
Published: 2004/08/06 23:21:58 GMT
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