What is insect allergy?
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.
Insect stings are the second most common cause of anaphylaxis outside medical settings. 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 autumn. 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, 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.
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 defences 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.
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. This can affect any part of your body including:
- Skin – feels clammy
- Head – feeling lightheaded, faint, collapsing or losing consciousness
- Heart – accelerated heartbeat
- Airways – wheezing and trouble breathing like fast or shallow
- Brain – confusion and anxiety
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 10cm 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 reactions often have a diameter of more than 10cm. An insect sting can even make your whole arm or leg swell up. These allergic reactions might look worrying but they’re often treated in the same way as a normal insect sting.
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 tweezers or a tick remover to grab the tick as close to your skin as you can. Pull it away without squeezing. Make sure you get the mouth parts out cleanly. Wash the bite with soap and water. Then rub in antiseptic cream.
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 antihistamine may help with swelling or itchiness.
An unusually large or painful local reaction may need medical attention and prescription antihistamines or corticosteroids.
Treatment for severe insect allergy reactions
Adrenaline is the main medication used to counteract anaphylaxis. Life-threatening allergic reactions can happen fast and need fast treatment. So your GP may prescribe a device called an adrenaline auto-injector. It’s for you to use in 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. Injectable adrenaline is not a replacement for medical attention. You should call an ambulance anyway 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 GP 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.
Specialist treatments for insect allergy
Specialist treatments may be able to help retrain your immune system so that it reacts differently. The treatment is called allergy immunotherapy 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.
Specialist treatment may be right for you if you’ve had a severe reaction previously. Your GP or allergist will assess and advise you.
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 clover and dandelions.
- wear perfume, brightly coloured clothing, shiny buckles or jewellery. Looking and smelling like a flower may prove irresistible to a stinging insect.
- drink from open fizzy drink cans. The sweet scent may attract stinging insects that can crawl inside without you noticing.
- leave rubbish 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.