What is insect allergy?

What is insect allergy? It’s when you react to insect stings or bites with symptoms that can be severe. This is a wasp stinger

This is what a wasp stinger looks like. Anyone who’s had a close encounter with one will be familiar with the raised red bump after the sharp ouch. For most people insect stings and bites are a nuisance and nothing more. But more widespread swelling can be a symptom of allergy. Insect stings can also cause a life-threatening allergic reaction called anaphylaxis.

This type of severe reaction only happens in around 3% of American adults who get stung. Even so, it’s natural to feel a little wary whenever you hear buzzing. In this article we’ll explain insect allergy and give you practical advice on how to avoid being stung or bitten.

When is insect allergy season?

Insect allergy is generally not a year-round problem unless you live somewhere tropical. Stinging insects like bees, wasps, yellow jackets and hornets tend to be active from spring to early fall. That’s when conditions are warm and plants are pollinating. If you travel, beware of other insects that may pose a risk, like fire ants in the southern states of the US.

Insect allergy: the inside story

Insect allergy refers to allergic reactions to insect stings (and insect bites) mainly in the Hymenoptera order. This includes bees, wasps, yellow jackets, hornets and fire ants. Insect allergy can also be triggered by insect bites from certain mosquitoes, bed bugs, kissing bugs, fleas, flies, other types of ants and ticks. Ticks are technically not insects. They're arachnids like spiders and dust mites. But because they bite they're often grouped together with biting insects causing allergies. That's why we're talking about them here.

What is anaphylaxis?

Woman on her mobile calling for an ambulance. Anaphylaxis, the most severe allergic reaction, can be life-threatening

If you’re allergic to insect venom or saliva your immune system makes Immunoglobulin E (IgE) antibodies to combat the toxin. You usually need to be stung or bitten twice before you develop allergy symptoms. The first time your body is prepping its defenses by creating the specific IgE antibodies. The next time you get bitten or stung, the antibodies might trigger a reaction and that causes insect allergy symptoms.

What are the symptoms of insect allergy?

It’s normal for everyone to get pain, redness and swelling around a sting site. Most people get an itchy lump from fire ants. Usually several insects attack at once, each one stinging again and again. The lump may calm down after about an hour. Over the next day a small liquid-filled blister is likely to form.

With insect allergy, local symptoms tend to be more intense. You can find a more detailed description below. More importantly, it can cause a severe allergic reaction called anaphylaxis. Symptoms typically involve more than one part of your body and may affect any of these:

  • Skin – flushed, pale, itching or hives
  • Head and neck – swelling of the tongue or throat
  • Heart and blood pressure – a weak or rapid pulse, low blood pressure (hypotension)
  • Gut – diarrhea, feeling or being sick
  • Airways – narrowing, which may cause wheezing and trouble breathing
  • Brain – dizziness or fainting

Anaphylaxis can happen suddenly, in minutes, or up to a few hours after you’re stung. Your body may go into shock and it can be life-threatening (more so for men than women it seems). The risk of having the same symptoms goes up once a systemic reaction has happened the first time.

What does insect sting allergy look like?

The size and nature of the swelling can help you tell the difference between a normal and an allergic reaction to an insect sting. Slight puffiness less than four inches in diameter around the puncture is to be expected. It usually calms down after a few hours but the itching may last several days.

A severe local reaction is a similar size but the swelling and redness is often more intense. Except on darker skin where erythema, the medical name for redness, can be harder to see. These symptoms may last up to a week. Large local allergic reactions often have a diameter of more than four inches. This might look worrying but is often treated in the same way as a normal insect sting.

An insect sting can sometimes make your whole arm or leg swell up. If the redness, swelling or hardening of the skin around the bite gets worse over 24 to 72 hours, be sure to see your healthcare provider as soon as possible.


Large local allergic reactions often have a diameter of more than four inches. This might look worrying but is often treated like a normal insect sting, with basic first aid.

Insect allergy: What to do if you’re stung

Mild to moderate allergic reactions usually respond to basic first aid. First remove all traces of the insect. If a bee has left its stinger behind, gently scrape it sideways with a fingernail. Don’t pinch it or you may squeeze more venom under the skin.

Ticks latch on to your skin. Use clean, fine-tipped tweezers to grasp the tick as close to your skin as possible. Pull upward with steady even pressure because any twist or jerk can cause the mouth-parts to break off. After removing the tick, thoroughly clean the bite area and your hands with rubbing alcohol or soap and water to prevent infection. Tell your healthcare provider what’s happened too as ticks can carry diseases.

How to relieve insect allergy symptoms

A cold compress or ice pack may help to ease pain and reduce swelling. Itchiness usually fades on its own. An over-the-counter painkiller may help to relieve discomfort. Corticosteroid cream or calamine lotion may help to ease itching, redness and swelling. An oral or topical antihistamine may help with swelling or itchiness.

Fire ant treatment is aimed at preventing an infection, which can happen if the blister bursts. Clean the blister with soap and water, even if it’s accidentally opened. Antihistamines and corticosteroids may also reduce itching here.

An unusually large or painful local reaction may need medical attention and prescription antihistamines or corticosteroids.

Simple guide to wasp
sting allergy

Sweet summer smells like strawberry attract wasps. Always cover food outside, especially if you’re allergic to wasp venom

Treatment for severe insect allergy reactions

Epinephrine is the main medication used to treat anaphylaxis. It’s another name for the hormone adrenaline. Life-threatening allergic reactions can happen fast and need fast treatment. So your healthcare provider may prescribe a device called an epinephrine auto-injector. It’s for you to use in the instance of a medical emergency.

It’s important to carry two auto-injectors with you at all times because a single dose may not be enough to reverse the reaction. Teach your family and friends how to use it too in case you can’t. You should also seek immediate medical attention, even if you use your auto-injector, in case you have a delayed secondary reaction.

You may want to carry a medical ID or wear a medical alert bracelet. This lets others know you’re allergic to insect stings and may need immediate treatment if stung.

Diagnosing an insect allergy

Your healthcare provider will take your medical history and a detailed account of your worst sting reaction. This is to help predict future risk. They will also ask if you know what type of insect stung you. Try to note:

  • Where you were when you were stung
  • What you did to get relief
  • Whether the insect left a stinger in your skin or not (honeybees leave a stinger)
  • A picture of the insect or even the insect itself

Some insect venoms, like yellow jacket and hornet, contain similar allergenic proteins. This causes cross-reactions and you may get allergy symptoms from more than just your trigger. Skin testing or blood tests can help make the diagnosis.

Is there a cure for insect allergy?

No there isn’t. But immunotherapy may be able to retrain your immune system so that it reacts differently. The treatment is also known as desensitization and it involves regular tiny doses of your particular allergen. A full course takes three to five years and it can reduce the risk of severe insect allergy symptoms.

Treatment for one insect allergy may address several different types of venom. For example, yellow jacket venom immunotherapy can tackle allergic reactions to hornets too. It’s because of the cross-reactivity we talked about before.

Insect venom immunotherapy may be right for you if you’ve had a severe reaction before or a skin reaction that spread beyond the sting site. Your healthcare provider will assess and advise you.

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Think you might be allergic to insect stings or bites? Maybe it’s time to look for a doctor nearby so you can ask their advice.
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11 ways to avoid insect allergy symptoms

Insect repellents don’t usually work on stinging insects so why not try these tips instead:


  • walk barefoot or wear open shoes in grass. Bees are attracted to white cloverand dandelions.
  • wear perfume, brightly colored clothing, shiny buckles or jewelry. Looking and smelling like a flower may prove irresistible to a stinging insect.
  • drink from open soda cans left outside. The sweet scent may attract stinging insects that can crawl inside without you noticing.
  • leave garbage uncovered.
  • swat a flying insect – especially if it’s trapped in a moving car. This can aggravate them. Remain calm, pull over and open the windows to allow it to fly away.


  • think ahead when planning outdoor activities. Summer hiking is better done with others rather than solo in case you get stung and need help.
  • cover up with long sleeves and pants when the risks of insect allergy symptoms are higher.
  • be alert when gardening as insect nests can be in bushes and trees. Yellow jackets set up home in the ground and in walls. Wear closed toe shoes, socks and gloves.
  • keep outdoor picnic and BBQ food covered.
  • pick fruit in your garden as soon as it ripens and clear away windfalls – just beware of stinging insects that may be hiding inside drawn by the smell.
  • leave windows and doors closed during insect allergy season – or cover them with thin netting.
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