A Research Review of Stinging Insects and Their Effects on Humans

Close-up of a red, circular reaction on the neck resulting from a yellow jacket sting.

Introduction

Earlier this week, one of our family members (a father) was stung by a yellow jacket in the backyard while spraying the nest with a water hose. Initially, he felt a brief stinging sensation behind his neck but did not immediately realize he had been stung. A relative later noticed a bright red area at the site of the sting, and although there was no pain, the spot began to itch. This event highlights how unpredictable and concerning insect stings can be, especially for those who might experience severe reactions.

Stings from insects such as bees, wasps, hornets, and yellow jackets can cause pain and fear for many people. In some individuals, stings trigger serious or even life-threatening allergic reactions, making rapid medical attention necessary. This paper reviews the most common types of stings, possible reactions, and recommended treatments.

Overview

Stinging insects can deliver venom into the skin, which sometimes leads to significant swelling, redness, and pain. A small number of people may experience severe, life-threatening reactions called anaphylaxis, which requires immediate medical care.

Insect Types:

Several insects are known to cause strong reactions when they sting:

1. Honey Bees and Bumble Bees

2. Yellow Jackets, Yellow Hornets, White-Faced Hornets, and Paper Wasps

3. Fire Ants, Harvester Ants, Bulldog Ants, and Jack - Jumper Ants

(Note: Fire ants are not discussed in depth in this paper.)

Insect Sting Reactions

When an insect stings, the stinger can inject venom into the skin. Removing the stinger right away can help reduce how much venom enters the skin, but most venom is released within seconds. You can remove the stinger using any quick method; specialized techniques (like scraping) are not necessary if they slow you down.

Most people will develop a local reaction around the sting site, while some individuals may develop a severe allergic reaction.

Local Reaction

Immediately after a sting, most people experience:

• Sharp or burning pain

• Swelling and redness of the skin

These symptoms usually improve within a few hours.

Large Local Reaction: About 10 percent of people develop a larger area of redness and swelling, sometimes 4 inches (10 cm) or more, which can take 1 to 2 days to reach its peak and then slowly go away over 5 to 10 days.

• A large local reaction does not necessarily mean you will develop anaphylaxis if stung in the future.

• Only about 5 to 10 percent of people who have a large local reaction end up having anaphylaxis later.

• If you have a large local reaction, talk to a healthcare provider about what to do if stung again.

Local Reaction Treatment

To reduce pain and swelling after a sting, you can:

1. Apply a cold compress. Use a cold, damp washcloth or wrap ice in a cloth and place it on the area.

2. Take an antihistamine if itching develops (e.g., cetirizine, sold as Zyrtec).

3. Use a pain reliever such as ibuprofen (Advil, Motrin, etc.) if needed.

If these steps do not help or if pain and swelling worsen, call your healthcare provider.

Allergic Reaction

In some people, insect stings can cause an allergic reaction, often appearing quickly. Symptoms may include:

• Hives, redness, or swelling of areas away from the sting site (e.g., swollen lips after a sting on the hand)

• Belly cramps, nausea, vomiting, or diarrhea

• Hoarse voice, shortness of breath, or difficulty breathing

• Lightheadedness, dizziness, or passing out

A severe allergic reaction, also known as anaphylaxis, can happen even the first time you are stung. This condition can be life-threatening and requires immediate medical attention.

Severe Allergic Reaction Treatment

If you develop signs of anaphylaxis, seek emergency care immediately:

1. Call 911 (in the United States) or your local emergency number.

2. Do not drive yourself; wait for an ambulance so trained paramedics can begin treatment right away.

3. The primary treatment for anaphylaxis is an epinephrine injection. Epinephrine (adrenaline) is available as a prescription in prefilled syringes, known as epinephrine autoinjectors.

Quick administration of epinephrine can be lifesaving. Delaying treatment can increase the risk of serious complications.

Am I Allergic to Stings?

If you have ever developed symptoms of an allergic reaction or anaphylaxis after a sting, you should see an allergy specialist. At the specialist’s office:

• Your doctor will determine if you are allergic to insect stings.

• If you are found to be allergic, the specialist will teach you how and when to use an epinephrine autoinjector.

• You may also discuss whether allergy shots (immunotherapy) could reduce your chances of having a severe reaction in the future.

Allergy Testing

There are two main ways to test for insect sting allergies:

1. Blood tests

2. Skin tests

Sometimes both tests are needed. If these tests confirm that you are allergic, there is a greater risk of a serious allergic reaction the next time you are stung. Allergy shots can lower this risk.

Allergy Shots (Immunotherapy)

Allergy shots (also called venom immunotherapy) help your body become less sensitive to insect venom. These shots usually contain purified venom, starting with very small amounts and gradually increasing to a level that is roughly equal to two or more stings. This process reduces your body’s tendency to react severely if stung again.

Allergy shots are typically recommended if you have:

1. A history of severe allergic reaction (anaphylaxis) to an insect sting, and

2. Positive allergy tests (showing allergy to bee, wasp, yellow jacket, or hornet venom).

Treatment is usually done in an allergist’s office:

• You may receive shots one to three times per week for a few months, then

• Once every 4 to 12 weeks for at least three years.

Some people continue treatment for three to five years, while others continue longer, especially if:

• They had a life-threatening reaction in the past.

• They react to the allergy shots themselves, indicating a high sensitivity to venom.

• They feel very anxious about possible future stings and want long-term protection.

Even after completing immunotherapy, it is important to carry an epinephrine autoinjector as a safety measure.

Epinephrine (Adrenaline)

Epinephrine is the primary treatment for severe allergic reactions. If you have experienced anaphylaxis after an insect sting, you should always carry at least one epinephrine autoinjector, even in colder seasons. However, be aware that one or even two doses of epinephrine may not completely resolve a severe reaction, so it is still critical to seek emergency care immediately after using an autoinjector.

Avoiding Stings

Most bees and wasps are not aggressive unless they feel threatened or their nest is disturbed. Here are some tips to prevent stings:

• Wear closed-toe shoes and keep food/drink containers covered when eating outside.

• Wipe up any spilled food or beverages promptly and check open drink cans for yellow jackets.

• Avoid wearing bright colors or strong perfumes near nests, although these factors are not the main cause of stings.

• If you see a wasp nest near your home, do not remove it yourself. Call a pest control professional instead.

• If a stinging insect approaches you, move away slowly without flailing your arms.

• If swarmed by multiple insects, cover your mouth and nose, then run indoors or into a vehicle.

Conclusion

Being stung by a bee, wasp, hornet, or yellow jacket can be uncomfortable, and for some people, it may lead to dangerous allergic reactions. Recognizing the signs of anaphylaxis and seeking immediate medical attention can save lives. Those who have experienced severe stings before may benefit from allergy testing and immunotherapy to lower the risk of future reactions. Furthermore, simple preventive measures, such as avoiding nests and wearing protective clothing, can reduce the chance of getting stung. By understanding both the risks and treatments, individuals can better protect themselves and others from the potential dangers of insect stings.

References

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