For most people an insect sting (most commonly in New Zealand from wasps, honey-bees or bumble-bees) will result in moderate, short term symptoms and straight-forward treatment.
However, a small percentage of the population will experience a more serious general or anaphylactic allergic reaction to insect stings that can affect the whole body and may be life threatening. It is estimated 2 to 3 people die in New Zealand each year from insect sting reactions.
Common insect sting symptoms and treatment
Most people will experience pain, itchiness, redness and minor swelling around a bee or wasp sting site. First aid treatment for these symptoms include ice packs or wet cloths to reduce pain; and antihistamine tablets or lotions, hydrocortisone cream, vinegar or calamine lotion to remedy itching and inflammation. Symptoms generally subside after a few hours.
However, a small number of people may experience a much more serious anaphylactic reaction to insect stings, either immediately after being stung or in the subsequent few hours. Reactions that occur within four hours of the sting are classified as immediate, and reactions that occur more than four hours after the sting are classified as delayed. Generally, the sooner the reaction begins, the more severe it will be.
An anaphylactic reaction occurs when the body's antibodies respond to the insect venom by releasing chemicals such as histamine and serotonin that trigger the allergic reaction. Symptoms of a moderate general or anaphylactic reaction include:
- Hives or itching over the body
- Puffy eyelids
- Puffy lips
Symptoms of a severe anaphylactic reaction include:
- Swelling of the tongue
- Difficulty swallowing
- Hoarseness and wheezing
- Dizziness and light-headedness
- Difficulty breathing
- Anxiety and disorientation
- Nausea and vomiting
- Symptoms of shock such as rapid heartbeat, weak pulse and a drop in blood pressure
- Loss of consciousness or seizures.
All suspected anaphylactic reactions require prompt medical treatment. A reaction that may initially seem mild, may progress to being more severe.
Severe anaphylactic reactions need immediate treatment with a medication called adrenaline, given in the form of an injection. The main action of adrenaline is to strengthen the force of the heart's contraction and to open up the airways in the lungs. Adrenaline is usually sufficient to reverse the reaction, though more than one dose may be required to achieve this. Other medications that may also be used to further reduce the allergic reaction include corticosteroids and antihistamines.
Self-injectable adrenaline (eg: EpiPen) is available for people known to have anaphylactic reactions. The injection device is filled with adrenaline and is administered into the large muscle in the front of the thigh when an anaphylactic reaction is experienced. The device holds only one dose, so medical assessment after the adrenaline has been administered is crucial in case the reaction worsens and further doses of adrenaline are required.
If treatment with medications is unsuccessful, breathing may need to be assisted by the insertion of a breathing tube into the lungs. If the throat is too swollen for a breathing tube to be inserted, an incision into the trachea (tracheostomy) may be required. A tracheostomy allows the breathing tube to be inserted more directly into the lungs.
For allergies to bee and wasp stings, it is possible to reduce the severity of future reactions – or even prevent them altogether – through a treatment known as immunotherapy. This may also be referred to as desensitisation.
Immunotherapy uses insect venom to gradually build tolerance to the venom. Injections of small amounts of bee or wasp venom will be given every week until the amount of venom in a sting can be tolerated. Once this happens, maintenance injections will need to be given every few weeks for up to five years.
Immunotherapy is generally only recommended for severe anaphylactic reactions where there are breathing difficulties or loss of consciousness. It is not recommended for local reactions.
Avoidance measures to reduce the probability of a sting are important for allergic individuals. Allergy New Zealand recommends the following measures:
- Wear closed footwear when outside
- Limbs should be covered when outdoors
- Avoid strong perfumes - they can attract insects
- Avoid pastel coloured clothing
- Rubbish should be disposed of promptly - wasps are attracted to rubbish and rotting fruit
- Avoid eating sweets outdoors
- Have some one else do the gardening and the lawns
- A professional pest control agent should destroy wasp nests promptly
- Use an insect repellent.
If stung by a bee and the stinger remains embedded in the skin, remove it carefully. This can be done by scraping under the barbed stinger with a knife blade, fingernail or sharp clean object. Try not to grasp the stinger when pulling it out. This may only cause more venom to be injected. It is particularly important to remove the tip.
For those who experience severe reactions, have an emergency kit containing antihistamine tablets and self-injectable adrenaline with you at all times. This may also be appropriate for some people with mild reactions, in order to prevent the reaction from progressing to a more severe reaction.
Wearing a Medic Alert bracelet and carrying an identification card will provide helpful information to health professionals attending to you in the event of a severe anaphylactic reaction.
Further information and support
For further information and support about insect sting allergies contact your doctor or practice nurse, or contact:
Allergy New Zealand
Freephone: 0800 34 0800
Adult Health Advisor (2006) Insect bites and stings. Clinical Reference Systems. Health and Wellness Resource Centre. McKesson Health Solutions LLC.
Allergy New Zealand (2010) Insect sting allergy. Allergy New Zealand, Auckland.
Auckland Allergy Clinic (Date Unknown) Allergies to Stinging Insects. Auckland Allergy Centre. Auckland. http://www.allergyclinic.co.nz/guides/20.html
Last Reviewed – June 2013