What should I do if I’m bitten by a Noble False Black Widow spider?

Dr Muiris Houston takes a look at the health issues surrounding the insects

Two Waterford women were recently treated for severe bites from a Noble False Black Widow spiders– with one spending six days in hospital. Dr Muiris Houston takes a look at the health issues surrounding the insects.

What is the false black widow?

Steadoda nobilis or the Noble False Black Widow spider is a small, brownish spider, with variable cream markings on a bulbous body. It is not aggressive to humans; however when trapped in clothing the adult can sting, causing a substantial swelling. If not properly treated the bite can become infected.

A relatively recent arrival in Ireland, the breed of spider has now spread to 18 counties, according to researchers at the Ryan Institute in NUI Galway. False Widow spiders live close to buildings inhabited by people, so they flourish in cities rather than rural areas.

Although venomous, Noble False Black Widow bites are not fatal. But the swelling can be substantial, with inflammation lasting for several days. A dry necrotic wound may form after the inflammation subsides. The bite may become extremely itchy. A secondary infection may occur.


What should I do if I’ve been bitten?

Wash the affected area with soap and water. Apply a cold compress (a cloth cooled with cold water) or an ice pack to any swelling for at least 10 minutes. Raise or elevate the affected area if possible, as this can help reduce swelling. Avoid scratching the area, to reduce the risk of infection.

At what point should I seek medical advice?

If you’ve been bitten in your mouth or near your eyes. If a large area (around 10cm or more) around the bite becomes red and swollen. you have symptoms of a wound infection, such as pus or increasing pain, swelling or redness. you develop a fever, swollen glands or flu-like symptoms

Emergency hospital treatment is needed if any of the following occurs.: wheezing or difficulty breathing a swollen face, mouth or throat nausea or vomiting a fast heart rate dizziness difficulty swallowing. They are a sign of a possible severe allergic reaction.