Insect Sting Allergies

Diagnosing

If you are concerned that you may have an allergy to insect venom, your best option is to see an allergist.

Your allergist should take a detailed medical history, including questions about previous stings (how many there have been and where you were stung), your reaction to those stings (what you experienced, how long the reaction lasted and what you did to get relief) and any additional symptoms.

Your allergist may perform one or more tests to diagnose allergy to insect venom, such as a skin-prick test, an intradermal skin test or a blood test.

In the skin-prick test, a small amount of a liquid containing insect venom is placed on the back or forearm, which is then pricked with a small, sterile probe to allow the liquid to seep into the skin. If a raised, reddish spot forms within 15 to 20 minutes, that can indicate an allergy. In the blood test, a blood sample is sent to a laboratory to test for the presence of immunoglobulin E (IgE) antibodies to insect venom.

If the skin prick test is negative or inconclusive your allergist will likely recommend an intradermal skin test, in which a small amount of venom extract is injected just under the skin. The site is examined after about 15 minutes for signs of an allergic reaction. This test is considered more accurate than the skin-prick or blood tests in determining the presence of IgE antibodies. If both skin prick and intradermal skin tests are negative then your allergist may recommend a blood test.

The strength of a reaction to a skin or blood test does not indicate how severe your allergic reaction will be the next time you are stung.

Management and Treatment

Insect sting allergy is treated in a two-step approach:

1. The first step is the emergency treatment of the symptoms of a serious reaction when they occur.
2. The second step is preventive treatment of the underlying allergy with venom immunotherapy.

Life-threatening allergic reactions can progress very rapidly and require immediate medical attention. Emergency treatment usually includes administration of certain drugs, such as epinephrine, antihistamines, and in some cases, corticosteroids, intravenous fluids, oxygen and other treatments. Once stabilized, these patients sometimes require close observation in the hospital overnight.

Injectable epinephrine for self-administration is often prescribed as emergency rescue medication for treating an allergic reaction. People who have had previous allergic reactions and rely on epinephrine must remember to carry it with them at all times. Also, because one dose may not be enough to reverse the reaction, recent guidelines recommend keeping two doses of injectable epinephrine available and to activate emergency medical services if used. Even if symptoms improve after a single dose of epinephrine, immediate medical attention following an insect sting is recommended.

Venom Immunotherapy

The long-term treatment of insect sting allergy is called venom immunotherapy, a highly effective program administered by an allergist, which can prevent future allergic reactions to insect stings.

Venom immunotherapy involves administering gradually increasing doses of venom to decrease a patient’s sensitivity to the venom. This can reduce the risk of a future allergic reaction to that of the general population. In a matter of weeks to months, people who previously lived under the constant threat of severe reactions to insect stings can return to leading normal lives.

If you think you might be allergic to insect stings, talk to your allergist. Based on your past history and certain tests, the allergist will determine if you are a candidate for skin testing and immunotherapy.

Avoiding Insect Stings

Knowing how to avoid stings from fire ants, honeybees, wasps, hornets and yellow jackets leads to a more enjoyable summer for everyone. Stinging insects are most active during the late spring, summer, summer and early fall. Insect repellents do not work against stinging insects.

Yellow jackets will nest in the ground and in walls. Hornets and wasps will nest in bushes, trees and on buildings. Use extreme caution when working or playing in these areas. Avoid open garbage cans and exposed food at picnics, which attract yellow jackets. Also, try to reduce the amount of exposed skin when outdoors.

Effective methods for insecticide treatment of fire ant mounds use attractant baits. These baits often contain soybean oil and corn grits combined with chemical agents. The bait is picked up by the worker ants and taken deeper into the mound to the queen. It can take weeks for these insecticides to work.

Allergists recommend the following additional precautions to avoid insect stings:

• Avoid wearing sandals or walking barefoot in the grass. Honeybees and bumblebees forage on white clover, a weed that grows in lawns throughout the country.
• Never swat at a flying insect. If need be, gently brush it aside or patiently wait for it to leave.
• Do not drink from open beverage cans. Stinging insects will crawl inside a can attracted by the sweet beverage.
• When eating outdoors, try to keep food covered at all times.
• Garbage cans stored outside should be covered with tight-fitting lids.
• Avoid sweet-smelling perfumes, hair sprays, colognes and deodorants.
• Avoid wearing bright-colored clothing.
• Yard work and gardening should be done with caution. Wearing shoes and socks and using work gloves will prevent stings on hands and feet and provide time to get away from an unexpected mound.
• Keep window and door screens in good repair. Drive with car windows closed.
• Keep prescribed medications handy at all times and follow the instructions if you are stung. These medications are for immediate emergency use while en route to a hospital emergency room for observation and further treatment.

If you have had an allergic reaction to an insect sting, it’s important that you see an allergist.

Fire Ant Sting

Fire ant sting allergy treatment

Fire ant sting allergy is treated in a two-step approach:

• The first step is the emergency treatment of the symptoms of a serious reaction when they occur.
• The second step is preventive treatment of the underlying allergy with whole body extract immunotherapy.

Life-threatening allergic reactions can progress very rapidly and require immediate medical attention. Emergency treatment usually includes administration of certain drugs, such as epinephrine, antihistamines, and in some cases, corticosteroids, intravenous fluids, oxygen and other treatments. Once stabilized, these patients sometimes require close observation in the hospital overnight.

Injectable epinephrine is often prescribed as emergency rescue medication for treating an allergic reaction. People who have had previous allergic reactions and rely on epinephrine must remember to carry it with them at all times.

Also, because one dose may not be enough to reverse the reaction, recent guidelines recommend keeping two doses of injectable epinephrine available and to activate emergency medical services if used. Even if symptoms improve after a single dose of epinephrine, immediate medical attention following an insect sting is recommended.

What is a normal reaction to a fire ant sting, and how is it treated?

The severity of a fire ant sting reaction varies from person to person. One of the main differences between fire ants and other insects is that a usual sting event consists of multiple fire ants stinging. This is because when a fire ant mound is disturbed hundreds to thousands of fire ants respond. In addition, each ant can sting repeatedly. Each ant will bite and hold on with its mandibles (jaw) and sting several times. If not removed, this results in a little semi-circular pattern of stings. Since fire ants hold on with their mandibles, they often have to be pulled off individually and are not easily brushed off when they are stinging.

Almost all people stung by fire ants develop an itchy, localized hive or lump at the sting site, which usually subsides within 30 to 60 minutes. This is followed by a small blister within four hours. This usually appears to become filled with pus-like material by eight to 24 hours. However, what is seen is really dead tissue, and the blister has little chance of being infected unless it is opened. When healed, these lesions may leave scars.

Fire ant sting treatment is aimed at preventing secondary bacterial infection, which may occur if the pustule is scratched or broken. Clean the blisters with soap and water to prevent secondary infection. Do not break the blister. If a blister is accidentally opened, careful attention to keeping the area clean with soap and water should still prevent infection. Topical corticosteroid ointments and oral antihistamines may relieve the itching associated with these reactions.