Stinging nettles

Nettles are plants with sharp hairs on their leaves. If you touch them, these hairs inject irritants into the skin, making it itchy, red and swollen.

What stinging nettle is

Stinging nettle is a common weed. It is found in:

  • gardens
  • waste areas
  • near where animals live
  • around moist areas such as creeks.

In Aotearoa New Zealand there are 3 species:

  • the native 'ongaonga' (giant tree nettle)
  • the introduced variety 'urtica dioica'
  • the introduced variety 'urtica urens'.

Symptoms of nettle sting

Small exposure to nettles can cause:

  • burning
  • itching 
  • redness
  • swelling (occasionally small blisters will form)
  • local numbness.

Symptoms usually go away on their own within a few days. 

If a large area of your body is exposed, or you have been exposed for a longer period of time, you may experience:

  • uncoordination
  • tremor
  • muscle weakness
  • fainting. 

When to get immediate medical attention

While most nettle stings require no further treatment, seek immediate medical attention if you develop:

  • loss of co-ordination
  • faintness
  • tremor
  • muscle weakness
  • breathing problems
  • swelling under the skin
  • abdominal pain.

You should also seek medical attention if there is significant skin itching or rash that is not resolving with home treatment.

Self care for nettle stings

  • Wash the area with soap and water as soon as possible to relieve the sting and remove the nettle hairs. If no water is available, clean the area with a cloth or other available material.
  • Local symptoms of pain and itching can be relieved by applying a moistened cloth or ice pack to the area. It is also important not to scratch or rub the itchy areas.
  • Antihistamines may be effective in relieving local itching and swelling, while creams such as hydrocortisone containing creams can help reduce inflammation. These are available at your local pharmacy.
  • Use cool, light, bedding and clothing as this will also help relieve itching.
  • Avoid extreme heat — have lukewarm baths and showers.

The National Poisons Centre is available 24 hours a day on 0800 764 766 for advice on first aid and treatment of stings.

Treating nettle stings

When you are treating nettle stings do not give aspirin (acetylsalicylic acid) or aspirin-containing products to anyone 18 years or younger. There is a risk of a serious illness called Reye’s syndrome.

Take non-steroidal anti-inflammatory drugs (NSAIDs) with food or milk to prevent stomach irritation. Do not give NSAIDs to anyone with:

  • NSAID-induced asthma
  • increased risk of bleeding, such as ulcer disease, a bleeding disorder, if taking blood thinners (anticoagulants), or following surgery, significant trauma or major dental work
  • an allergy to NSAIDs.