Allergic Reactions to Insect Stings

Bee, wasp, yellow jacket, hornet or fire ant stings are the insect stings that most often trigger allergic reactions. However, most people are not 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 severity of an insect sting reaction varies from person to person. There are three types of reactions -- normal, localized and allergic:

• A normal reaction will result in pain, swelling and redness around the sting site.
• A large local reaction will result in swelling that extends beyond the sting site. For example, a person stung on the ankle may have swelling of the entire leg. While it often looks alarming, it is generally no more serious than a normal reaction.
• The most serious reaction to an insect sting is an allergic one (described below). This condition requires immediate medical attention.

What Are the Symptoms?

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

• Difficulty breathing
• Hives that appear as a red, itchy rash and spread to areas beyond the sting
• Swelling of the face, throat or mouth tissue
• Wheezing or difficulty swallowing
• Restlessness and anxiety
• Rapid pulse
• Dizziness or a sharp drop in blood pressure

Although severe 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
• Pimple-like spots
• Mild to moderate swelling
• Warmth at the sting site
• Itching

People who have experienced an allergic reaction to an insect sting have a 60% chance of a similar or worse reaction if they are stung again.

How Common Are Sting Allergies?

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

How Are Normal or Localized Reactions Treated?

First, if stung on the hand, remove any rings from your fingers immediately.

If stung by a bee, the bee 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. Do not squeeze the sac or pull on the stinger -- this will cause the release of more venom into the skin.

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

Apply a soothing ointment, like a hydrocortisone cream or calamine lotion and cover the area with a dry, sterile bandage.

If swelling is a problem, apply an ice pack or cold compress to the area.

Take an over-the-counter oral antihistamine to reduce itching, swelling and hives. However, this medication should not be given to children under 2 years of age or to pregnant women without prior approval from a doctor.

To relieve pain, take a nonsteroidal anti-inflammatory medication 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 medicines before taking it. Parents of children and people with medical conditions should consult a pharmacist if they have questions about a medicine's use.

How Are Allergic Reactions Treated?

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

In some cases, intravenous fluids, oxygen and other treatments are also necessary. Once stabilized, you are sometimes required to stay overnight at the hospital under close observation. People who have had previous allergic reactions must remember to carry epinephrine with them wherever they go.

Also, because one dose may not be enough to reverse the reaction, immediate medical attention following an insect sting is still recommended.

How Can I Avoid Being Stung?

You can lessen your chances of an insect sting by taking certain precautionary 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 country or wooded areas.
• Avoid wearing perfumes or brightly colored clothing. They tend to attract insects.
• If you have severe allergies, you should never be alone when hiking, boating, swimming, golfing or otherwise involved outdoors because you might need prompt medical treatment if stung.
• Use insect screens on windows and doors at home. Use insect repellents. Spray bedrooms with aerosols containing insecticide before going to bed.
• 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 the case of severe symptoms. For more information on where to get a MedicAlert bracelet, you can call 1-800-ID-ALERT.

What Are Epinephrine Sting Kits?

Epinephrine self-administration kits are important for you to use immediately after being stung, before you get to a doctor for treatment. The two most common have the brand names Ana-Kit and Epi-Pen. However, these kits should not be used as a substitute for medical intervention. 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 medicines.

You will need a prescription from your doctor to purchase one of these kits. Before using, be sure to let your doctor know about any medicine you are taking to prevent drug interactions.

How Can I Prevent an Allergic Reaction?

Allergic reactions to insect stings can be prevented with allergy shots. The treatment is about 97% effective in preventing future reactions and involves injecting gradually increasing doses of venom that stimulate your immune system to become resistant to a future allergic reaction.

If you've had an allergic reaction, it's important to 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 are a candidate for immunotherapy treatment.