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Insect Bites + Stings

Insect bites from mosquitoes and insect stings from wasps prove that very tiny things can create really big, and sometimes life-threatening reactions. Depending on what you're allergic to, your reaction may be limited to a certain body part, or spread across the body.

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Difference between insect stings and bites

Insect bites and stings can cause very serious allergic reactions, so it's important to understand the difference between them:

  • Insect bites: A local reaction (limited to where you were bitten) will happen if you're allergic to the insect's saliva.
  • Insect stings: A systemic reaction (throughout your body) will happen, and can require emergency medical attention if you're allergic to the insect's venom from its stinger.
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Local and systemic reactions cause your immune system to go into fight mode. It's important to understand your body's unique reactions, so you know what symptoms to look for and how to treat them.

Call 911 immediately if you're experiencing life-threatening symptoms from an insect sting.

Local reactions

These four main biting insects cause local reactions that are believed to be due to insect saliva:

  • Bedbugs
  • Black flies
  • Deer flies
  • Mosquitoes

Reactions to biting insects can be very uncomfortable, but they rarely cause severe or life-threatening reactions.

Local reactions usually start within minutes of the bite, with burning, itchy or swelling skin. Delayed swelling usually occurs 12–24 hours after the sting and can be bothersome.

Local reactions aren't typically dangerous and tend to be treated with antihistamines and ice packs to help calm swelling. However, more severe local reactions require intensive medical treatment.

Systemic reactions

There are four major classes of insects that can sting and cause systemic reactions:

  1. Ants (fire ants)
  2. Bees (honey and bumble bees)
  3. Vespids (yellow jackets, white-faced hornets, yellow hornets)
  4. Wasps (paper and mud wasps)

All stinging insects have a stinger at the end of their abdomen. The stinger is attached to a venom sack that contracts and discharges venom. The amount of venom that enters your body depends on how long the stinger is in your skin.

When an insect sting causes anaphylaxis, a small amount of the venom protein causes your cells to release substances that produce the allergic reaction.

Symptoms for systemic reactions typically appear within an hour of the sting. You may experience the following:

  • Chest tightness
  • Difficulty swallowing
  • Dizziness
  • Flushed skin
  • Full-body hives
  • Lightheadedness
  • Shortness of breath
  • Swelling and itching in the throat
  • Tingling of lips and hands
  • Wheezing

It's critical to know these symptoms are a medical emergency and require immediate attention. The most severe phase of a systemic reaction occurs in the first hour, so it's very important to seek medical attention immediately.



A go-to diagnostic for fully understanding which insect venoms you might be allergic to is skin testing. Many insect venoms share common allergens, so it may be possible that you’re allergic to multiple kinds of insects.

If you’ve had a systemic reaction to insect bites before, your skin test will potentially reveal that you are allergic to any insect venom.



Our doctors have expertise in treating stings and bites with prevention methods, medications and desensitization therapy.


By following a few simple outdoor tips, you can help prevent future insect stings:

  • Avoid digging in the ground
  • Avoid hanging around food that attracts yellow jackets
  • Forgo off-trail hiking
  • Routinely check for yellow jackets and wasp nests around your home and hire a professional to remove them


Systemic allergic reactions can be frightening and possibly life-threatening, so it’s very important to always have medication on hand. Your doctors may prescribe an adrenaline injector, such as an EpiPen®.

It's always best to seek emergency medical attention if a reaction is in progress, just in case it worsens.


We often recommend desensitization if you are commonly in high-risk situations or if you find yourself in areas where medical attention is not readily available. Medical trials show that desensitization is effective and will prevent serious allergic reactions for most people.

So, how does it work? Desensitization therapy helps you become less sensitive to an allergy by receiving injections of the allergen over 12 weeks. Your doctor will gradually increase your dosage each week to make you less sensitive to your allergy.

It’s common to receive maintenance doses for 3–5 years before completely wrapping up your desensitization treatment plan.

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