Treating spider bites

The whitetailed spider is more common than the katipō and redback. It is often found in houses, including on the walls and ceilings.

Whitetailed spiders will bite if provoked. But in most cases the bite will cause little harm.

Whitetailed spider bites are not considered poisonous to humans. A recent Australian study has shown no evidence linking necrotic ulcers (destroyed skin) to whitetailed spider bites.

Symptoms of a whitetail spider bite

The whitetailed spider bite can be painful. You may have some:

• swelling
• redness
• itchiness
• a burning feeling at the bite site.

These symptoms will go away, and there are no long lasting effects.

How to treat whitetailed spider bites

If you think you have been bitten by a whitetailed spider you can treat this with simple first aid. These spiders do not cause skin damage or ulcers. If you think you have been bitten, clean the wound with antiseptic, or warm soapy water. Put ice on the skin to reduce any pain or swelling — do not put this directly on the skin. Wrap the ice in cloth to prevent cold burns.

Contact your healthcare provider if the bite area:

• is very red
• is painful 
• blisters 
• appears infected
• forms an ulcer.

If you need advice on first aid and bite treatment, call the National Poisons Centre on 0800 764 766

The katipō and the redback spider are the only venomous spiders found in Aotearoa New Zealand. Only the adult females are capable of biting humans. Bites from both species are extremely rare.

Symptoms of a katipō spider bite

Symptoms of a katipō bit include:

• pain at the bite site which spreads to other areas and becomes more intense
• sweating 
• difficulty breathing 
• abdominal cramps

Symptoms of a redback spider bite

Redbacks will only bite when disturbed or trapped in clothing. Their bite will feel like a sharp pinprick. Symptoms can include:

• redness at the bite site
• pain
• sweating
• stomach pain
• aches in muscles and joints
• feeling sick and throwing up
• increased heart rate
• increased blood pressure.

Generally these occur quite soon after being bitten. Serious reactions are uncommon and are not likely to develop in less than 3 hours. Venom is not always introduced with the bite. If it is, most reactions to the venom are moderate

How to treat a katipō or redback spider bite

Mild symptoms can generally be managed at home with oral pain relief such as paracetamol and ibuprofen

If symptoms become more severe seek medical attention straight away. Hospitals can provide safe and effective treatment (anti-venom).

If you think you have been bitten by a katipō or redback spider

If you think you have been bitten, clean the wound with antiseptic, or warm soapy water. Put ice on the skin before travelling — do not put this directly on the skin. Wrap the ice in cloth to prevent cold burns.

Do not apply pressure to the bite or drink alcohol after being bitten.