Allergic Reactions to Insect Stings

Bee, wasp, yellow jacket, hornet, or fire ant are most often the insect stings to 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 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 five to 10 days.
• The most serious reaction to an insect sting is a systemic allergic reaction known as anaphylaxis(described below). This condition requires immediate medical attention.

What Are the Symptoms of an Allergic Reaction?

Symptoms of a severe allergic reaction (called an anaphylactic reaction or anaphylaxis) 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, lips or tongue
• 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
• Mild to moderate swelling
• Warmth at the sting site
• Itching

People who have experienced a severe systemic 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 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. 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 and then apply an antiseptic.

If swelling is a problem, apply an ice pack or cold compress to the area. Elevate 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. However, this medication should not be given to children under 2 years of age or to pregnant women without prior approval from a doctor. The antihistamine can also make you drowsy, so do not 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 medicines before taking it. Parents of children and people with medical conditions should consult a pharmacist if they have questions about a drug's use.

How Are Serious Allergic Reactions Treated?

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.

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. Honey bees 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 severe allergies, you should never be alone when hiking, boating, swimming, golfing, or otherwise involved outdoors, as you may need prompt 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 the case of severe symptoms.

What Are Epinephrine Sting Kits?

If you are at risk for a severe systemic reaction, epinephrine self- administration kits are important for you to use immediately after being stung, before you get to a doctor for treatment. Do not wait to see if you are having a reaction before administering the pen because by then it may be too late.

The two most common are 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 drugs.

You will need a prescription from your doctor to purchase 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, be sure to let your doctor know about any medication 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 (also known as immunotherapy). The treatment is 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.

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