Wasp sting allergy: What you need to know now

Wasp allergy is an overreaction of the immune system to wasp venom, resulting in more significant symptoms than normal.¹ Hives, itching and swelling can spread beyond the sting site and last for several days. Or a sudden severe allergic reaction, called anaphylaxis, could affect your whole body and be life-threatening.²

Wasps tend to be more aggressive than bees and sting when they feel threatened, for instance if you try shooing them away from your food. It’s a defence mechanism.³ The short sharp blast is meant to make you leave the wasp alone.² It’s important to understand this so you can reduce the risk of it happening.

Read more about how an allergic wasp sting looks and feels compared to a typical sting (with pictures) and how to get an allergy diagnosis. The chances of being stung are higher at some times of year than others. That’s covered too, as is what to do after a sting depending on your symptoms. Find answers to frequently asked questions about allergy to wasp venom, plus a list of differences between wasps and bees, which can also trigger insect sting allergy.²

Normal wasp sting vs an allergic reaction

Allergic reactions to wasp stings are over 10cm across and the swelling could spread up your arm or leg. Large local reactions may last for days and can usually be treated with first aid, anti-itch creams and other symptom relief. A severe systemic allergic reaction (anaphylaxis) is a medical emergency.²

A normal wasp sting usually lasts a few hours. A large local reaction (allergic) may take 24-48 hours to reach its peak and be evident for days, according to Allergy UK.²

Wasp sting allergy: What different symptoms mean

Wasp sting allergy may only cause mild to moderate symptoms but the reaction can escalate quickly. Draw a circle round the sting site, take photos and note down the timing of any changes. If you suspect anaphylaxis – maybe you’re feeling dizzy or sick – you need emergency adrenaline and an ambulance.²

It’s also important to seek medical advice if you were stung more than once, have had a severe reaction before or your symptoms keep getting worse after the first 48 hours.^2,4 Call your GP or dial 111.

Read more the treatment for anaphylaxis that you can self-administer.

Common mild to moderate wasp allergy symptoms

Here are some of the common (non-severe) allergic symptoms that can happen after a wasp sting:^2,5

• Pain
• Redness (may be harder to see on dark skin)
• Swelling beyond the sting site
• Itching
• Hives
• Flushing

Severe allergic reactions: Wasp sting anaphylaxis

Wasp sting anaphylaxis affects the whole body and most life-threatening reactions happening within 30 minutes.² The telltale signs and symptoms can include:⁵

• Flushed or pale skin, widespread itching or hives
• Swelling of the tongue or throat, difficulty swallowing
• Breathing fast or struggling to breathe, wheezing
• Diarrohea, feeling or being sick
• Weak or rapid pulse, palpitations
• Drop in blood pressure, shock
• Confusion, sense of impending doom
• Dizziness, fainting

An anaphylactic reaction is more common with bee stings than wasp stings but it’s still important to be able to recognise it.³

When is wasp allergy season?

Wasp stings tend to happen most in late summer and autumn, making this the riskiest time for allergic reactions.² Queen wasps emerge from hibernation in the spring and build a nest. The colony expands over the summer, until the drones are forced out and look for food – like your picnic.⁶

Yellow jackets are a type of wasp too. Scientists call their erratic late summer behavior ‘delirium’. It’s why yellow jackets also tend to sting more, triggering wasp sting allergy, in August and September.⁷ 

Wasp allergy season comes to an end when temperatures drop and the colony dies.⁶

How do you find out if you've got wasp sting allergy?

You know what wasp allergy symptoms look like and think you may be affected. It’s time to talk to your GP about getting a diagnosis. They will want a description of the insect that stung you, details of your worst insect sting reaction and your medical history. They may also suggest allergy testing. 

You may be allergic to one stinging insects and also get symptoms from another.⁷ That’s because proteins in venom from wasps, yellow jackets and hornets can look so similar it causes a cross-reaction.^1,7 The allergy tests will help work out if wasps are the trigger or something else.

Wasp allergy and sensitisation

It usually takes at least two wasp stings to develop the allergy. The first time, your immune system registers the venom as a threat and produces protective Immunoglobulin E (IgE) antibodies to detect the venom in the future. That’s sensitisation and you could have an allergic reaction if stung again.¹ 

The role of the IgE antibodies is to keep watch for the venom and then trigger different cells to act and get rid of it from your body. That reaction is the cause of your wasp allergy symptoms.¹

Wasp sting allergy can develop at any age.⁹ Children may outgrow it, except if they have a moderate to severe reaction. That makes it more likely they could have a systemic allergic reaction to insect venom later in life, according to the study Outcomes of Allergy to Insect Stings in Children, with and without Venom Immunotherapy (New England Journal of Medicine, 2004).¹⁰

Treatment options: What to do after being stung by a wasp

An ice pack or cold compress may be all that’s needed for wasp stings, including large local reactions, but you could also try antihistamine or a corticosteroid cream. An over-the-counter painkiller may help too unless the swelling is particularly painful or widespread, in which case see your doctor.²

Anaphylaxis always needs immediate medical attention as it can be fatal. This is also a reason to consider venom immunotherapy, a wasp sting allergy treatment that can reduce the risk.¹¹

What is the emergency treatment for a wasp sting?

The emergency treatment for a wasp sting anaphylaxis is adrenaline and the doctor may prescribe it for you to self-administer. The advice is to carry two adrenaline devices with you at all times, in case of emergencies, because a single dose may not be enough.⁹ 

Call an ambulance even if you feel better because it’s possible to have a delayed secondary reaction some hours later. Wearing a medical alert bracelet will tell people you’re allergic to wasp stings so they know how to help you.⁵

Is there a cure for wasp allergy?

There is a treatment to tackle the underlying cause and it may be recommended to people who’ve had widespread hives and swelling or anaphylaxis. The goal of venom immunotherapy is to retrain the immune system to react differently and offer protection in the future.¹²

A course of venom immunotherapy involves regular doses of wasp allergen for around 3 years. It can be available for adults and children, depending on eligibility. Your doctor can tell you more.¹¹

The short version

Symptoms of wasp sting allergy include hives, itching and swelling in areas other than the sting site (a normal reaction tends to be localised). These respond to cold compresses and simple over-the-counter sting medications. But an anaphylactic reaction can be life-threatening and you should seek immediate medical attention.² A course of insect venom immunotherapy may lower the risk of another large local reaction or systemic reaction in the future.¹¹ Ask your doctor about it.