Patient education: Insect allergy (The Basics)

What is an insect allergy? — An insect allergy is a condition that causes a serious and sometimes deadly reaction to an insect sting.

Insects that cause the most serious reactions include:

●Honey bees

●Yellow jackets

●Hornets and wasps

●Fire ants

These insects have special "stingers" on the back of their bodies that can shoot venom into your skin.

What is a normal reaction to an insect sting? — Insect stings can cause the area right around the sting to swell, turn red, hurt, and feel hot. These changes usually go away after an hour or 2.

Some people get a lot of swelling around the sting that can last for days. This is called a "large local reaction." It is not dangerous, and it is not the same as an allergic reaction.

What are the symptoms of an allergic reaction to an insect sting? — If you have an allergy to insect venom, the sting can cause a normal reaction (pain, swelling, and redness around the sting) plus other symptoms throughout your body. These symptoms include:

●Flushing – Flushing is when your skin turns red or purple and feels hot, especially on your face.

●Hives – These are raised patches of skin that are very itchy (picture 1).

●Angioedema – This is swelling of the face, eyelids, mouth, tongue, hands, and feet (picture 2).

Some people have a more serious reaction, called "anaphylaxis." Call for an ambulance (in the US and Canada, call 9-1-1) if you are stung by an insect and you suddenly:

●Have trouble breathing, become hoarse, or start wheezing (hear a whistling sound when you breathe)

●Start to swell, especially in the throat or around the face, eyelids, mouth, hands, or feet

●Develop belly cramps, nausea, vomiting, or diarrhea

●Feel dizzy or pass out

Is there a test for an insect allergy? — Yes. If you had a severe reaction after an insect sting, you should see an allergy specialist. You will need a blood or skin test, or sometimes both tests.

How is an insect allergy treated? — Treatments include:

●Allergy shots – These shots will make you much less likely to have a serious reaction if you get stung again. You will likely get shots 1 to 3 times a week for a few months. After that, you will get a shot once a month for at least 3 years. Some people get monthly shots for up to 5 years or longer. The shots work very well to prevent another severe reaction.

●Epinephrine – This medicine helps stop the symptoms of an allergic reaction. It comes in pre-filled injectors, so you can give yourself an injection (shot) if needed. If you had a serious reaction to an insect sting in the past, you should always carry at least 1 epinephrine injector at all times.

What can I do to reduce the chances of getting stung? — You can:

●Stay calm and slowly back away if you see a stinging insect. Do not wave your arms or try to swat it.

●Keep foods and drinks covered when you are outside, and clean up any spills right away.

●Avoid wearing sandals and open-toed shoes in the summer.

●Avoid doing things that might disturb an insect nest, such as mowing the lawn or pruning a hedge.

●If you find an insect nest in or near your house, call a pest control service to get rid of the nest safely. Do not try to do it yourself.

●If you live in an area that has fire ants, avoid stepping on ant mounds and wear shoes and socks when outside.

More on this topic

Patient education: Insect bites and stings (The Basics)
Patient education: Anaphylaxis (The Basics)

Patient education: Bee and insect stings (Beyond the Basics)
Patient education: Imported fire ants (Beyond the Basics)
Patient education: Anaphylaxis symptoms and diagnosis (Beyond the Basics)
Patient education: Anaphylaxis treatment and prevention of recurrences (Beyond the Basics)
Patient education: Using an epinephrine autoinjector (Beyond the Basics)