Spider Bites – treatment, symptoms and first aid
Spider bites can cause severe allergic reactions (anaphylaxis) in some people and it is difficult to know if a spider bite is dangerous or not.
3 types of spiders:
1. Big black spiders that also include the funnel-web spiders and any large, black-looking spider.
2. Redback spiders can easily be identified and their bites can cause pain and other problems in the body but not necessarily life-threatening.
3. All other spiders in Australia are harmless.
Treat it as an emergency and call triple zero (000) to ask for an ambulance if you have been bitten by a big black spider.
Big black spiders – Funnel-web spider:
- Found in highlands, eastern coastal areas and Victoria.
- Shiny and black, 1cm-5cm in size and powerful fange.
- Can survive for many hours in a swimming pool and can be aggressive when trapped in a house.
- Can be found all around Australia in urban areas but less common in winter months. They build webs in dry sheltered areas like rocks and sheds.
- Females are black with an orange-red stripe running across the upper abdomen with sizes of 1cm. These markings are less noticeable with the males and the males can reach sizes up to 4cm.
- Female bites are dangerous but will only bite when you directly touch the web.
First aid for a big black spider’s bite
It is very dangerous when bitten by a funnel-web or mouse spider and you might need to provide emergency care — including cardiopulmonary resuscitation (CPR) if needed.
If bitten stay calm and follow these steps:
- Apply pressure (Immobilisation bandage – these bandages are recommended for spider bites and should bandage the area that was bitten)
- Do not move around
- Keep the bitten limb low down
- Immobilise the limb by splinting
- Wait for the ambulance to arrive
- Keep the person calm and still until medical help arrives.
The Australian Museum has instructions for catching a spider for identification purposes
How to apply a pressure immobilisation bandage:
First, apply the pressure bandage tight over the bite markings.
Next, apply a heavy elasticised roller bandage, starting from above the toes or fingers and over the bitten markings upwards on the limb to the body. On either side of the bite you would need to split the limb and the joints.
The person should be kept still and the limb completely at rest. With a pen, mark the site of the bite on the bandage.
You can find the guide to pressure immobilisation bandages on the AU Resuscitation Council’s website.
Spider bites can lead to severe allergic reactions when bitten and their bodies react to the bite within minutes that can lead to anaphylactic shock (anaphylaxis). Anaphylactic shock can be fatal and is very serious.
- Breathing and talking can be difficult
- Swelling of the throat and tongue with ongoing cough
- Constant dizziness and can collapse
- Young children can go pale and sagging
- Abdominal pain or vomiting
Call triple zero (000) for an ambulance if someone experiences anaphylaxis.
You can manage a known severe allergy by dispensing adrenaline via an autoinjector (such as an EpiPen).
The Australasian Society of Clinical Immunology and Allergy recommends that the only treatment for a severe allergic reaction is adrenaline and you can also visit the website Choosing Wisely Australia for more details.
For more information on anaphylaxis, including setting up a personal action plan, go to www.allergy.org.au.
Cardiopulmonary resuscitation (CPR)
Cardiopulmonary resuscitation is needed in some cases when bitten by a spider.
The healthdirect’s page can guide you on how to perform CPR and a poster of first aid resuscitation procedures can be printed from St John Ambulance Australia.
First aid for other spider bites
For all other spider bites, including bites from redback spiders, apply a cold compress or ice pack (wrapped in a clean cloth) for 15 minutes directly over the bite to relieve the pain.
If further symptoms or signs of infection develop, you would need to seek medical assistance..