The three families of insects that cause the most allergies are vespids (wasps, hornets), bees, and ants. Relatively few people in the United States experience life-threatening reactions to them.

According to the American College of Allergy, Asthma, and Immunology, it’s more common to be afraid of an insect bite or sting than to be allergic to one.

Most people who get stung by an insect have a minor reaction. This may include some redness, swelling, or itching at the site of the sting. This normally goes away within hours.

For some people, however, an insect sting can cause a severe reaction or even death. In the United States, between 1.6% and 5.1% of people experience life-threatening reactions from insect stings each year, and approximately 72 people in the United States die each year from insect stings.

This article reviews the types of insects that can potentially cause an allergic reaction, the symptoms of an allergic reaction, and what to do if you think you’re having an allergic reaction.

There are three families of insects that cause the most allergies. These are:

  • vespids (Vespidae): yellow jackets, hornets, wasps
  • bees (Apidae): honey bees, bumblebees (occasionally), sweat bees (infrequently)
  • ants (Formicidae): fire ants (commonly cause anaphylaxis), harvester ants (less common cause of anaphylaxis)

Rarely, bites from the following insects may cause anaphylaxis:

  • mosquitoes
  • bed bugs
  • kissing bugs
  • deer flies

What is anaphylaxis?

Anaphylaxis is a severe and sudden allergic reaction that can develop just seconds after exposure to an insect bite, sting, or other allergen. This type of reaction results in life threatening symptoms, including:

If you experience anaphylaxis, seek immediate emergency help. Without treatment, anaphylaxis can result in death.

Allergic reactions to an insect bite or sting are serious. Symptoms may include one or more of the following:

  • itching, swelling, or a hive-like rash in areas other than the sting site
  • stomach cramping, vomiting, diarrhea, or intense nausea
  • tightness in the chest and difficulty in breathing
  • a hoarse voice or swelling of the throat or tongue that may cause difficulty swallowing

An even more serious allergic reaction is called anaphylaxis. It can occur minutes after the sting or bite and may be life-threatening. Symptoms include difficulty breathing due to a swelling of the airways, a sudden drop in blood pressure, and cardiac arrest, if left untreated.

Both types of allergic reactions require immediate medical attention. Call 911 if you suspect you are experiencing an allergic reaction to an insect sting or bite.

In the case of anaphylaxis, a dose of epinephrine (adrenaline), typically administered in an auto-injector, may be required in addition to immediate medical care.

For serious or severe allergic reactions, seek immediate medical care.

If you’ve been bitten or stung by an insect and are only experiencing mild symptoms, such as swelling, itching, or redness, over-the-counter antihistamines, such as diphenhydramine (Benadryl), may help relieve symptoms.

Your immune system responds to unfamiliar substances with cells that can detect the specific invader. One component of this system is antibodies. They allow the immune system to recognize unfamiliar substances, and they help eliminate them.

Multiple types of antibodies exist, each with a particular role. One of these subtypes, immunoglobulin E (IgE), is associated with the development of allergic reactions.

If you have an allergy, your immune system becomes overly sensitized to certain substances. Your immune system mistakes these substances for invaders. In the course of responding to this mistaken signal, the immune system produces IgE antibodies specific to that substance.

The first time a person with an insect allergy is stung, the immune system may produce a relatively small amount of IgE antibodies that are targeted toward that insect’s venom.

If stung again by the same kind of insect, the IgE antibody response is much more rapid and vigorous. This response leads to the release of histamine and other inflammatory chemicals that cause allergy symptoms.

If you’re concerned about having an allergic reaction to an insect sting or bite, make an appointment to see an allergy specialist. They can identify what insects (and other allergens) you’re allergic to and recommend treatment and prevention options.

If you have had an allergic reaction to an insect sting, you have a greater chance of having a similar or more severe reaction if stung again by the same kind of insect.

The best way to avoid an allergic reaction, of course, is to avoid being stung. Tips to avoid getting stung include:

  • remove insect hives and nests from your home and yard
  • wear protective clothing when you are outdoors
  • avoid wearing bright colors and strong perfumes when you are outdoors, as this may attract insects
  • be careful when eating outside, insects are often attracted to the smell of food

If you have had a serious allergic reaction in the past, you should wear a medical alert identification bracelet and carry an epinephrine auto-injection kit.