What is an insect sting allergy?

Anyone stung by a bee or wasp is likely to have a painful swelling where they were stung. This is not a sign of an allergic reaction and for most people, a sting is not dangerous.

Some people have an allergic reaction to the venom in the sting. This causes more swelling than usual but tends to be mild. Any swelling of greater than 10 cm is referred to as a large local reaction. For a small number of people, allergic reactions can be systemic which means they affect whole body systems, for example widespread swelling, a drop in blood pressure or breathing difficulties.

Systemic allergic reactions can be life-threatening. This is known as anaphylaxis. If you know you are at risk of a serious reaction, the idea of being stung can be frightening, but there are steps you can take to reduce the risks and help you feel more confident. This includes getting medical advice, carrying prescribed medication, and taking care to avoid being stung.

Download our insect sting allergy factsheet

Download the factsheet

Who is at risk?

Anyone can become allergic to an insect sting. You are more at risk of a serious allergy if you are stung often or have multiple stings. Beekeepers, for example, are more at risk of serious reactions. People with a rare condition called mastocytosis are also at higher risk.

Having other allergies such as hay fever or food allergies does not put you at higher risk of a serious allergy to insect stings.

What are the symptoms?

The symptoms of a serious allergic reaction usually come on quickly, within minutes of being stung. Serious symptoms are often referred to as the ABC symptoms and can include:

  • AIRWAY – swelling in the throat, tongue or upper airways (tightening of the throat, hoarse voice, difficulty swallowing).
  • BREATHING – sudden onset wheezing, breathing difficulty, noisy breathing.
  • CIRCULATION – dizziness, feeling faint, sudden sleepiness, tiredness, confusion, pale clammy skin, loss of consciousness.


You might also have:

  • itching and swelling away from the site of the sting
  • severe abdominal (stomach) pain, vomiting or diarrhoea


The term for this more serious reaction is anaphylaxis (pronounced anna-fill-axis).

Most healthcare professionals consider an allergic reaction to be anaphylaxis when it involves difficulty breathing or affects the heart rhythm or blood pressure. Any one or more of the ABC symptoms above may be present.

In extreme cases there could be a dramatic fall in blood pressure. The person may become weak and floppy and may have a sense of something terrible happening. Any of the ABC symptoms may lead to collapse and loss of consciousness and, on rare occasions, can be fatal.

Getting a diagnosis

If you have had symptoms away from the site of a sting, for example widespread hives or swelling, or any ABC symptoms as mentioned above, see your GP who can refer you to a specialist allergy clinic if needed. They can find a clinic in your area from the British Society for Allergy and Clinical Immunology (BSACI).

Some people have large swellings at the site of a sting which get bigger over 24-48 hours. If you have a swelling of more than about 10cm, visit your GP. If you are stung again in future, you will probably have a similar reaction, but there is a slight risk you could have a more significant reaction. Most people won’t need to see a specialist, but it can be a good idea for people who are more likely to get stung, such as beekeepers.

If you are at all worried about insect sting allergy, visit your GP.

Watch our podcasts

Allergies to Bee & Wasp Stings

Simon and expert Dr Andrew Whyte explore the importance of allergy testing, immunotherapy, and emergency response. Dr Andrew Whyte works at the Department of Allergy and Immunology at Derriford Hospital, providing care to patients with immunodeficiency and allergy from across the South West Peninsula. Dr Whyte, along with the other consultants at Eden Unit, supervise the UKAS-accredited immunology laboratories at Derriford Hospital and the Royal Devon and Exeter Hospital and provide advice and guidance to requestors from across the region.

How is an allergic reaction treated?

If you have a small allergic reaction at the site of a sting, antihistamine medicine can help. You can buy these from pharmacies. You can also use a cold compress, such as a cloth dampened with cold water. These usually help even if the sting is very painful.

If you have a serious allergic reaction that affects whole body systems (anaphylaxis) this needs to be treated with adrenaline straight away. If you are at higher risk of anaphylaxis, you may be prescribed adrenaline to use in an emergency.

Adrenaline comes in pre-loaded adrenaline auto-injectors (AAIs) that are designed to be easy to use. Make sure you know how and when to use them. Ask your healthcare professional to show you how to use your specific brand of AAI. You can also find help and training videos on the manufacturer’s website and get a free trainer device to practise with.

You must carry two AAIs with you at all times, as you may need to use a second one if your symptoms don’t improve after five minutes or get worse.

Adrenaline Auto-Injectors

The adrenaline auto-injectors prescribed in the UK are:

Avoiding insect stings

If you are allergic to insect stings, you can take steps to minimise the risk of getting stung. For example:
  • right_arrow_orange_icon Avoid walking around in bare feet or sandals when outdoors.
  • right_arrow_orange_icon Avoid using strong perfumes during the summer as they attract insects. Products such as hairsprays and other cosmetics can contain strong perfumes.
  • right_arrow_orange_icon Keep your arms and legs covered when outside, if possible.
  • right_arrow_orange_icon If a bee or wasp comes near you, don’t try and swat it. Move away from it slowly and calmly. If it lands on you, try not to panic. Just wait. The insect will usually fly away after a few seconds.
  • right_arrow_orange_icon If you find a nest of wasps or bees in your house or garden, telephone the local authority or an insect expert to come and remove the nest. Do not try to do this yourself.
  • right_arrow_orange_icon After eating or drinking, make sure you don’t have any traces of food or drink around your mouth, as these will attract insects.
  • right_arrow_orange_icon If you find a nest of wasps or bees in your house or garden, contact the local authority or an insect expert for advice. Never try to move a nest yourself.
  • right_arrow_orange_icon If you are planning to eat outside, find an area where there are no wasps or bees. If you can’t find anywhere, it’s better to bring your picnic inside than to risk being stung.
  • right_arrow_orange_icon Keep food and drink covered as food attracts insects. Always look at what you’re eating or drinking before you take a bite or a sip in case an insect has landed on it. Wasps can slip into drinks cans so the safest option may be boxed drinks with a straw, or bottled drinks and keep the lid on between sips.
  • right_arrow_orange_icon When you’re outside, avoid open rubbish bins as these can attract insects.

Types of insects

The insects that cause most serious allergic reactions in the UK are wasps and honeybees. People are not usually allergic to both bees and wasps, although allergy tests can be positive for both.

Serious reactions to bumble bees and to hornets are also possible. In other parts of the world, other species of bees, wasps, ants and other insects can cause allergic reactions.

Allergy tests will help to tell you which type of insect you are allergic to but they won’t be able to predict how serious any future reactions will be.

  • Bees

    When a bee stings, it leaves its stinger in the skin. The stinger has a venom sac attached to it.  It takes a few minutes for all the venom to pass through the stinger into the skin, so removing the stinger quickly lowers the risk of a serious reaction. To remove the stinger and venom sac, flick the venom sac upwards with one quick scrape of a finger nail or credit card. Avoid squeezing the venom sac as this will inject more venom into the skin.

    Beekeepers should take special care. Always wear protective clothing when collecting swarms or honey. If you are a beekeeper and you’re at risk of a serious reaction to bee stings, speak to your doctor about how to continue beekeeping safely.

  • Wasps

    Wasps can sting many times as they don’t leave their sting in the skin. Wasps are often aggressive, especially towards the end of the season (late summer and autumn) when they eat any decomposing foods. From autumn until the end of the year, wasps become sleepy, keep perfectly still and stop buzzing so it is much easier to accidentally touch or step on one.

    Wasps die off in the winter except for Queen wasps which hibernate in sheltered places in trees or buildings. Be aware that they may tuck themselves into nooks such as a bed, curtains, gloves, boots, or a stack of plant pots.

  • Hornets

    Hornets are an orange-brown colour and are larger and louder than wasps. Despite their threatening size and sound they are not as aggressive as wasps. But when they do sting the amount of venom usually makes the stings very painful.

Immunotherapy treatment

If you have a serious allergy to insects, your GP or allergy specialist may suggest immunotherapy. This is where you have injections of a tiny amount of venom and build up to larger amounts over time. The aim is to desensitize your immune system so that you don’t have an allergic reaction if you get stung. Immunotherapy is also known as desensitisation.

Key messages

  • right_arrow_orange_icon Most allergic reactions to insect stings are mild.
  • right_arrow_orange_icon In a small number of people, insect stings can be life-threatening.
  • right_arrow_orange_icon If you have had a systemic (whole body) allergic reaction to a sting, see your GP and ask for a referral to an allergy specialist.
  • right_arrow_orange_icon Swelling at the site of the sting is unlikely to be a serious problem but if you are at all worried, see your GP.
  • right_arrow_orange_icon If you are prescribed adrenaline auto-injectors (AAIs), make sure you know how to use them and carry two with you at all times.
  • right_arrow_orange_icon There are steps you can take to avoid being stung, and immunotherapy can be an option for some people.

Download our insect sting allergy factsheet

Download the factsheet