Thursday 22 August 2019

Spider experts warn of False Widow's venom bites after Waterford woman left hospitalised for six days

Researchers from Venom Systems Lab, NUI Galway, Dr Michel Dungon and John Dunbar say a bite from a False Widow spider could lead to Steatodism syndrome
Researchers from Venom Systems Lab, NUI Galway, Dr Michel Dungon and John Dunbar say a bite from a False Widow spider could lead to Steatodism syndrome

Aoife Walsh

Spider experts have warned of toxin-filled venom from the False Widow spider after a bitten Waterford woman was left hospitalised for six days.

Researchers from Venom Systems Lab, NUI Galway, Dr Michel Dungon and John Dunbar say a bite from a False Widow spider could lead to Steatodism syndrome, and admitted that not enough is yet known about their venom, making it difficult to say how harmful it could be.

They said: "The Noble False Widow is the only species of spiders capable of delivering a medically significant bite in Northern Western Europe.

"The symptoms described by victims of confirmed bites include a very fast onset of moderate to intense pain around the bite site quickly expanding to the whole limb, redness of the skin - first around the bite, quickly expanding to the whole limb, swelling first around the bite, and sometimes expanding to the whole limb".

The venomous bite can also cause goosebumps, chills, sweat, fever, malaise and a cramping sensation as venom affects the central nervous system.

Dr Dungon added that in rare instances, "small dermonecrosis" can appear around the bite site. This causes the skin to blacken and die at the bite site.

"The venom of Steatoda nobilis contains some toxins that are similar to the ones of the 'true' black widows.

"The extreme blistering could also be due to bacterial infections, which may be either a direct result of the bite as the fangs of the spider contain bacteria, passed into the victim’s flesh, or a secondary infection from scratching the bite site, passing bacteria from the fingernails to the flesh."

Maria Condon from Ferrybank, Waterford was hospitalised for six days (Photo: WLR FM)
Maria Condon from Ferrybank, Waterford was hospitalised for six days (Photo: WLR FM)

"Overall, the symptoms have been deemed serious enough to get their own specific name. Being bitten by a False Widow may result in Steatodism, the syndrome encompassing all the symptoms we have mentioned, so we don’t think that they are deadly, but we think that they can send you to bed for a couple of days and even to the hospital in some more extreme cases.

They added: "We don’t know everything yet about its venom and the symptoms it can produce as we are the only ones working on it in the world, as far as we know, but we are working on it."

If you are unfortunate enough to come across a Nobel False Widow, Dr Dungon and Mr Dunbar advise that you keep the spider and contact them: "We recommend that victims keep the spider (even if it is dead), to contact us at NUI Galway Venom System Lab and to go and see their GP if they develop swelling, extensive redness or if they feel “ill”.

"It is only by getting more verifiable reports that we will be able to inform GPs, hospitals and the public about the real risks associated with false widow bites."

Photo of three-year-old's spider bite (Photo: Cormac Melia)
Photo of three-year-old's spider bite (Photo: Cormac Melia)

While the Noble Widow spiders bear a strong resemblance to many other of their six-legged creepy crawlies, they are actually very different.

The experts explained: "They are actually quite different spiders but they look superficially similar, which is why we speak about 'false' widows. 'True' and 'false' widows belong to the same main family of spiders called the comb-footed spiders - they use little combs on their back legs to spin their silk.

Photo of three-year-old's spider bite (Photo: Cormac Melia)
Photo of three-year-old's spider bite (Photo: Cormac Melia)

"False widows are represented by three species in Ireland, but the one we always hear about is the Noble False Widow - scientific name Steatoda nobilis. They measure the size of a 2 euro coin in leg span, have a shiny black back with cream coloured designs. They lack the famous red hourglass shape present on the belly of almost all black widows," they explained.

The concerns come after two Waterford women were treated for severe bites, with one spending almost a week in hospital as a result.

Maria Condon from Ferrybank, Waterford was hospitalised for six days in University Hospital Waterford after blisters formed on and underneath her leg within minutes of having been bitten by a spider which ran up the inside leg of her jeans.

Speaking on WLR FM's ‘Deise Today’ to Damien Tiernan, Ms Condon said she was told by hospital staff the bite was from a Noble False Widow spider.

In Sligo, a three-year-old was left with a second degree infection after a spider bit him while he was walking through a field with his father.

His father, Cormac Melia said: "There is a field beside my house where I walk my dogs. My sons always come out with me. The grass is very long in it and my son was wearing shorts. When we were walking he said he got stung by a nettle and he was very itchy. About an hour or two later this appeared.

He continued: "The next morning is was much worse. It started with a small blister and that bursted, so we thought it would heal but it spread bigger and bigger and had a massive blister on it. My wife brought him to the doctors and he was given 2 very strong antibiotics and a steroid cream and were given strict instructions that if it got bigger we were to bring him to A&E. On the letter it said second degree infection caused by spider bite. Thankfully he's on the mend now but the second picture was taken a few days ago and it looks like it will scar."

The Noble False widow spider, who were first spotted for the first time in Bray, Co Wicklow in 1997, originate from the Canary Islands and Madeira, and have been brought to Ireland and the UK through imported goods.

They are now found in all major towns, from Dublin, where they occur in very large numbers in and around houses, to Wexford, Cork, Galway or Sligo.

However, the experts say the False widow is not a  "particularly aggressive" species, and "usually bite only when they are squeezed between the skin and clothes or a bedsheet.

"People can safely put them into a glass and throw them outside. I would recommend this over killing them, as people can easily mistake them for other, harmless native spiders. It’d be a shame to kill a bunch of useful native spiders thinking that they are invasive false widow," said Dr Dungon.

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