Bee and wasp sting allergies and anaphylaxis

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 that two or three 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 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 creams, hydrocortisone cream, or calamine lotion to reduce itching and inflammation. Stings hurt or itch for one to two days but the swelling may last for up to a week. 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. Generally, the sooner the reaction begins, the more severe it will be.

Anaphylaxis symptoms

An anaphylactic reaction occurs when the body's immune system overreacts to the insect venom by releasing chemicals such as histamine that trigger the allergic reaction.

Symptoms of a moderate general or anaphylactic reaction include:

• Hives or itching over the body
• Flushed or pale skin
• Puffy eyelids
• Puffy lips.

Symptoms of a severe anaphylactic reaction include:

• Swelling of the tongue
• Difficulty swallowing
• Swelling around the lips and eyes
• Hoarseness and wheezing
• Dizziness and light-headedness
• Difficulty breathing
• Anxiety and disorientation
• Nausea and vomiting
• Symptoms of shock such as rapid heartbeat, weak pulse, pale skin, and a drop in blood pressure
• Loss of consciousness or seizures.

A severe anaphylactic reaction is a medical emergency — dial 111 and ask for an ambulance if someone is displaying symptoms of anaphylactic reaction.

Anaphylaxis treatment

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 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.

Anaphylaxis prevention

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 de-sensitisation.

Immunotherapy uses insect venom to gradually build tolerance to the venom. It is usually performed by an immunology or allergy specialist. Injections of small amounts of bee or wasp venom are given under the skin repeatedly over a prolonged period of time 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. Skin prick tests can be performed to identify people likely to suffer more severe reactions to insect stings.

Avoiding stings

Avoidance measures to reduce the probability of a sting are important for allergic individuals. Allergy New Zealand recommends the following measures:

• Wear closed footwear and clothes that cover your limbs when outside
• Avoid strong perfumes and bright coloured clothing — they can attract insects
• Rubbish should be disposed of promptly — wasps are attracted to rubbish and rotting fruit
• Avoid consuming sweets and sugary drinks outdoors
• If a stinging insect is flying around you, walk away slowly without waving your arms around
• Have someone else do the gardening and the lawns
• Stay away from known beehives and wasp nests
• Call a professional pest control agent to 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 the blunt side of a knife, the edge of a credit card or piece of paper, or clean fingernail. 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.

After removal of the sting, wash the area with soap and cold water. Do not scratch the sting area as doing so will worsen the itch and swelling and increase the risk of infection.

People who have had severe reactions, should carry an emergency kit containing antihistamine tablets and self-injectable adrenaline (eg: EpiPen) with them 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

Website: www.allergy.org.nz
Freephone: 0800 34 0800

References

St Aubyn Crump, V. (2013). Insect sting allergy (Web Page). Auckland: Auckland Allergy and Eczema Clinic. http://www.allergyclinic.co.nz/insect-sting-allergy [Accessed: 19/08/20]
Ministry of Health (2017). Bee and wasp stings (Web Page). Wellington: New Zealand Government Ministry of Health. https://www.health.govt.nz/your-health/conditions-and-treatments/accidents-and-injuries/bites-and-stings/bee-and-wasp-stings [Accessed: 19/08/20]
Wright, B. (2013). Bee and wasp stings (Web Page). Hamilton: DermNet NZ. https://dermnetnz.org/topics/bee-and-wasp-stings/ [Accessed: 19/08/20]

Last Reviewed: August 2020

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