False Widow Spider Bites

As you will have no doubt read, the false widow is the UK’s most venomous spider. Whilst this is true the bite itself is no worse than a wasp or bee sting. That said, wasp and bee stings kill around 10 people every year in the UK, a figure that would result in mass hysteria if a spider were the culprit. It has to be said that all these fatal stings resulted in allergic reactions that were the true culprit.

What are the symptoms of a false widow spider bite?

The actual bite itself is not normally felt until afterwards when there is a varying amount of pain. This is largely related to the amount of venom that is injected. As a guide though, the bite has been compared to a wasp sting with a similar stinging, burning pain initially. With time at least some degree of swelling is likely to occur often accompanied with local numbness.

The venom of the false widow and other spiders in the Steatoda group can also cause steatodism. This presents as set of symptoms, most notably intense pain radiating from the bite, fever, nausea, headache, malaise, lethargy and even chest pains. Such severe reactions are apparently rare and there has never been a fatality in the UK from a false widow spider bite.

In general the symptoms of the bite will disappear within one to three days.

Please note: All the stories you may have read about people’s arms nearly having to be amputated and pus filled open wounds are not directly attributable to the bite of the false widow. If these are in any way connected to a bite (which is doubtful in some cases) then it is the result of a secondary bacterial infection, the same that could occur from any cut or graze.


  • The first step in treating a false widow spider bite is to wash the area with soap and water. This is to prevent infection which will be infinitely worse than the bite.
  • To try and minimise swelling by using a cold compress (do not place ice directly on the skin as this may burn). A bag of frozen peas is ideal for this and should be applied to the bite for around 10 minutes.
  • Applying a bite spray or antiseptic cream will help prevent infection. Also, many creams have local anesthetics which will reduce discomfort and itching.
  • Some sources suggest administering antihistamines to counter any possible allergic reaction and anaphylactic shock.
  • The condition of the person should be monitored and if it appears to worsen a trip to A & E may be warranted.
  • It is always a good idea to try and catch the spider so medical staff know what they are dealing with. Obviously make sure you don’t get bitten again doing this!


  • Antibiotics should not be taken unless there is an infection (or definite risk of infection). They will not help.
  • Trying to suck or cut out the ‘poison’ will not work and are more likely to result in the wound becoming infected.

The venom

In common with their more infamous cousin, the black widow, and in fact most biting spiders, the false widow delivers a neurotoxic venom (the other type being necrotic venom). These toxins interfere with the nervous system and can result in a range of symptoms from cramps to interfering with breathing.
Fortunately the poison of the false widow is nowhere near as potent as that of the black widow which is credited with killing more people than any other spider. It is said that the venom of the black widow is around 50 times stronger than that of a rattle snake.

So, how dangerous is it?

I’m sure by now most of you will have read a story or two somewhere in the media about false widow spider bites. Cases such as the grandfather who ended being hospitalised and having to have his leg drained. Or the shopper who collapsed after being bitten 10 times on the neck. These appear to be particularly severe reactions to what is usually no worse than a wasp sting. In the former case the severity of the bite seems to have been caused by a secondary bacterial infection. Whether this can be directly attributed to the spider is not obvious.

There have been articles claiming the spiders bite caused ‘flesh to decay’. I believe this is not the case and merely sensationalist journalism. As mentioned the venom of the false widows is a neurotoxin and not necrotic (flesh rotting). Whilst some spiders, such as the South American brown recluse, do have bites causing this kind of infection no such link has been proved with the false widow. It seems either a case of mistaken identity or a complication associated to an injury.


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