Stinging plants

There are several stinging plants in Australia that can cause pain if your skin touches them. This article explains the best first aid treatment if this happens, depending on the type of stinging plant.

It’s important to be aware that stings from plants can cause a severe allergic reaction (anaphylaxis) in some people. Learn more about first aid treatment for severe allergic reactions in the ‘anaphylaxis’ section below.

What are stinging nettles?

Stinging nettles (Urtica dioica, Urtica incisa, Urtica urens) are plants that are commonly regarded as weeds in Australia. Stinging nettles are often found in damp areas. They grow about one metre high. Leaves are positioned opposite each other on the stem.

Nettles have tiny hairs on the leaves and stem. If you touch them, you will get a painful sting.

Contact with the plant can cause:

• your skin to go red
• itching
• swelling
• an intense burning sensation

Your rash may be painful for a few hours after you are stung. If you are particularly sensitive, your symptoms may last for up to 36 hours.

Generally, nettle stings will not cause lasting problems unless you have an allergy to the nettle sting.

What should I do if I get stung by a stinging nettle?

There are several things you can do to treat the sting from a stinging nettle.

• Wash the affected area with soap and water. This helps to treat the pain and remove the nettle hairs. If you don’t have water, clean the area with a cloth.
• Put a damp cloth or ice pack on the area. Don’t scratch or rub it, even if it’s itchy.
• Use antihistamines to treat itchiness and swelling, and hydrocortisone cream to treat inflammation.
• Avoid too much heat — take lukewarm showers, wear light, cool clothing and use light bed sheets.

What are stinging trees?

Stinging trees are trees with leaves, stems and fruit that are covered in tiny hairs that cause intense stinging if your skin touches them. The sting can get worse for the next 20 minutes to 30 minutes. The pain has been described as being stung by wasps.

Stinging happens because the hairs carry a neurotoxin. A neurotoxin is something that damages your nervous system. The stinging-tree neurotoxin doesn’t break down over time or from cold or heat. Stinging tree leaves that have been kept for nearly 100 years can still cause pain.

The hairs pierce your skin and can break off. The sting lasts as long as the hairs remain below your skin; until your body physically forces them out. The pain from broken hairs can last for days to months.

Stinging trees are generally found in rainforests in the eastern parts of Australia, from northern New South Wales to Cape York in Queensland. There are 4 common types of stinging trees.

1. Atherton Tableland stinger (Dendrocnide cordata), which grows up to 4 metres high.
2. Giant stinging tree (Dendrocnide excelsa), which grows up to 35 metres high.
3. Gympie-gympie (Dendrocnide moroides), which grows up to 4 metres high.
4. Shiny leaf stinging tree (Dendrocnide photinophylla), which grows up to 20 metres high.

The fruit of these trees look a bit like mulberries, but can be white, pink and dark red in colour.

The gympie-gympie is thought to have the most painful sting. The leaves of the gympie-gympie can range in size from a thumbnail to more than 50cm wide.

What should I do if I get stung by a stinging tree?

If you get stung by a stinging tree:

• seek medical attention
• do not rub the area — this can break off the hairs and make them very difficult to remove
• remove visible hairs with tweezers
• use adhesive tape or hair-removal wax strip to remove the finer hairs
• do not scratch or rub the area since this may cause the hairs to sink deeper into your skin

If possible, use wax strips to remove any remaining hairs of the stinging tree. Don’t put liquid wax directly on your skin. This will cause the hairs to break, causing you more pain. It will also make the hairs difficult or impossible to remove.

How can I prevent being stung?

You can help protect yourself from stinging plants by wearing:

• long thick pants
• a long-sleeved shirt
• a hat
• thick gardening gloves

Remember that your clothes may collect the hairs from stinging plants while you are walking so it’s important to be careful when taking your clothes off.

As a rule, avoid contact with plants with furry, heart-shaped leaves and saw-toothed edges.

Anaphylactic shock

Sometimes, people can have a severe allergic reaction to a stinging plant.

In cases of severe allergic reaction, your whole body can react within minutes to the sting. This can lead to anaphylactic shock. Anaphylactic shock is very serious and can be fatal.

Symptoms of anaphylactic shock are:

• difficult or noisy breathing
• difficulty talking
• hoarse voice
• a swollen tongue
• persistent dizziness or collapse
• swelling or tightness in the throat
• pale and floppy (young children)
• wheeze or persistent cough
• abdominal pain or vomiting