Allergic Reactions to Insect Stings

Medically Reviewed by Poonam Sachdev on April 20, 2023
6 min read

Bee, wasp, yellow jacket, hornet, and fire ant are the insect stings that most often trigger allergic reactions. But most people aren't allergic to insect stings and may mistake a normal sting reaction for an allergic reaction. By knowing the difference, you can prevent unnecessary worry and visits to the doctor.

The seriousness of an insect sting reaction varies from person to person. There are three types of reactions – normal, localized, and allergic:

  • A normal reaction results in pain, swelling, and redness around the sting site.
  • A large local reaction results in redness and swelling that extends beyond the sting site. The swelling may extend about 4 inches from the sting site over a period of a couple of days. It should get better within 5 to 10 days.
  • The most serious reaction to an insect sting is a systemic allergic reaction known as anaphylaxis (described below). This requires medical attention right away.

Symptoms of a severe allergic reaction (called an anaphylactic reaction or anaphylaxis) may include one or more of the following:

  • Trouble breathing
  • Hives that appear as a red, itchy rash and spread to areas beyond the sting
  • Swelling of the face, throat, lips, or tongue
  • Wheezing or trouble swallowing
  • Restlessness and anxiety
  • A rapid pulse
  • Dizziness or a sharp drop in blood pressure

Although serious allergic reactions are not that common, they can lead to shock, cardiac arrest, and unconsciousness in 10 minutes or less. This type of reaction can occur within minutes after a sting and can be fatal. Get emergency treatment as soon as possible.

A mild allergic reaction to an insect sting may cause one or more of the following symptoms at the site of the sting:

  • Pain
  • Redness
  • Mild to moderate swelling
  • Warmth at the sting site
  • Itching

People who have had a severe systemic allergic reaction to an insect sting have a 60% chance of a similar or worse reaction if they're stung again.

About 2 million Americans are allergic to the venom of stinging insects. Many of these people are at risk for life-threatening allergic reactions. About 50 deaths each year in the U.S. are linked to allergic reactions to insect stings.

First, if you're stung on the hand, remove any rings from your fingers right away.

When you're stung by a bee, the insect usually leaves a sac of venom and a stinger in your skin. Remove the stinger within 30 seconds to avoid receiving more venom. Gently scrape the sac and stinger out with a fingernail or a stiff-edged object like a credit card. Don't squeeze the sac or pull on the stinger – this will release more venom into the skin.

Wash the stung area with soap and water, and then apply an antiseptic.

If swelling is a problem, apply an ice pack or cold compress to the area. Raise the area above the level of your heart, if possible, to decrease the swelling.

Take an over-the-counter oral antihistamine to reduce itching, swelling, and hives. But this medication should not be given to children under 2 years of age or to pregnant women without approval from a doctor. The antihistamine can also make you drowsy, so don't drive or operate heavy machinery after taking it.

To relieve pain, take a nonsteroidal anti-inflammatory drug (NSAID) such as ibuprofen.

In general, pregnant women should consult their doctors before taking any over-the-counter medicine.

Also, carefully read the warning label on any medicine before taking it. Parents of children and people with medical conditions should talk to a pharmacist if they have questions about a drug's use.

An anaphylactic reaction is treated with epinephrine (adrenaline), either self-injected or given by a doctor. Usually, this injection will stop the development of a severe allergic reaction.

In some cases, IV fluids, oxygen, and other treatments are also needed. Once stabilized, you might have to stay overnight at the hospital under close observation. People who have had previous allergic reactions must remember to carry an epinephrine injector (Adrenaclick, Auvi-Q, EpiPen , or Symjepi) with them wherever they go.

Also, because one dose may not be enough to reverse the reaction, you'll still need to get medical attention right away after an insect sting.

You can lessen your chances of an insect sting by taking certain measures:

  • Learn to recognize insect nests and avoid them. Yellow jackets nest in the ground in dirt mounds or old logs and walls. Honeybees nest in beehives. Hornets and wasps nest in bushes, trees, and on buildings.
  • Wear shoes and socks when outdoors.
  • Wear long-sleeved shirts, long pants, socks, and shoes when in wooded areas.
  • Avoid wearing perfumes or brightly colored clothing. They tend to attract insects.
  • If you have serious allergies, you should never be alone when hiking, boating, swimming, golfing, or otherwise involved outdoors, as you may need fast medical treatment if stung.
  • Use insect screens on windows and doors at home. Use insect repellents.
  • Spray garbage cans regularly with insecticide, and keep the cans covered.
  • Avoid or remove insect-attracting plants and vines growing in and around the house.
  • A severely allergic person should always wear a MedicAlert bracelet and keep a self-care kit (described below) on hand for emergency use in case of severe symptoms.

If you're at risk for a severe systemic reaction, use an epinephrine self-administration kit right after you're stung, before you get to a doctor for treatment. Don't wait to see if you're having a reaction before using the pen, because by then, it may be too late.

These kits shouldn't be used as a substitute for medical help. You should still see a doctor after being stung. Epinephrine alone is not always enough to reverse serious allergic sting reactions and may cause serious side effects in some people with heart conditions or people who are taking certain drugs.

The two most common are the brand names Ana-Kit and EpiPen. You'll need a prescription from your doctor to buy one of these kits. Each kit has two pens in case a repeat dosage is needed. Carry it with you at all times. Before using it, be sure to let your doctor know about any medication you are taking to prevent drug interactions.

Your doctor will show you how to use your kit. To use an EpiPen:

  • Take the pen out of the package and remove the blue safety cap.
  • Hold it in your fist, with the blue cap pointing up and the orange tip (where the needle comes out) down toward your outer thigh.
  • Put the orange tip against the side of your thigh, then jab it in until you hear a click.   
  • Hold it there for a full 3 seconds until all the medicine is injected.

You can prevent allergic reactions to insect stings with allergy shots (also known as immunotherapy). This treatment is 97% effective in preventing future reactions. It involves injecting gradually increasing doses of venom that cause your immune system to become resistant to a future allergic reaction.

If you've had an allergic reaction, talk to an allergist, a doctor who specializes in the diagnosis and treatment of allergic disease. Based on your history and test results, the allergist will determine if you're a candidate for immunotherapy treatment.