Heat, humidity, pollen and mold spores. If these aren't enough to make allergy sufferers dread the impending dog days of summer, here's one more thing to add to the list: insects.
Stinging insects, including bees, hornets, yellow jackets, wasps, and fire ants -- and biting insects such as mosquitoes and "kissing bugs" (Triatoma) -- are most plentiful in late July, August and early September.
These uninvited guests in picnics, parks -- and even in beds -- send more than half a million people each year to hospital emergency rooms and cause at least 50 deaths, according to the American College of Allergy, Asthma and Immunology (ACAAI). Experts believe that many more deaths occur each year that are never identified as anaphylaxis caused by insect sting or bite allergies. At particular risk are the more than two million Americans who have had allergic reactions to bites or stings.
"Allergic reactions to insect stings and bites require immediate medical attention," said Richard D. deShazo, M.D., chair of the ACAAI Insect Hypersensitivity Committee and an allergist at University of Mississippi Medical Center, Jackson, Miss. "People who know they are allergic should never be without an emergency kit containing epinephrine (adrenaline). If you experience any symptoms of an allergic reaction for the first time from an insect sting or bite, get to an emergency room right away."
These symptoms include hives, itchiness, swelling in areas other than the sting site, difficulty breathing, dizziness, hoarse voice and swelling of the tongue. In severe reactions, the person loses consciousness and can have cardiac arrest.
Stinging insects
"Once you've had an allergic reaction to an insect sting, it's important to see an allergist. You have a 60 percent chance of having another similar or worse reaction if you're stung again," Dr. deShazo said. "You should have an allergist prescribe an epinephrine kit and teach you and your family members how to administer the injection. You also should discuss whether you're a candidate for allergy shots, also known as immunotherapy, that desensitize you to insect stings.
"People with venom allergies don't have to live in fear of insects. Studies have shown that allergy shots, which introduce tiny purified extracts of insect venom are 97 percent effective in protecting allergic people from potentially life-threatening reactions to insect stings," he said.
Insect repellents do not work against stinging insects, but there are ways to minimize your chances of being stung, without having to confine yourself to staying indoors.
"Don't look like a flower, smell like a flower or act like a flower," Dr. deShazo said. "Bees are attracted to flowers and they'll be attracted to you if you dress in bright colors and floral prints, wear strong perfumes and walk barefoot in the grass among the clover that bees love so much."
Most people are not allergic to insect stings and should recognize the difference between an allergic reaction and a normal or large local reaction.
Knowing how to avoid stings from fire ants, bees, wasps, hornets and yellow jackets leads to a more enjoyable summer for everyone. Here are some additional tips from the American College of Allergy, Asthma and Immunology:
-- Keep food covered when eating outdoors.
-- Don't drink soft drinks from cans. Stinging insects are attracted to the sweetness and may crawl inside the can.
-- Garbage cans stored outside should be covered with tight-fitting lids.
-- Keep window and door screens in good repair. Drive with car windows closed.
-- Keep prescribed medications handy at all times and follow the attached 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 a child who is allergic, make sure teachers, camp counselors and other adult supervisors know, and that the child has an emergency epinephrine kit.
If you or your child have had an allergic reaction to an insect sting, it's important to see an allergist-immunologist to be evaluated for an allergy shot program that immunizes against future allergic reactions.
Fire ants
Fire ants bite to hold on, and then can sting repeatedly.
According to Richard M. Weber, M.D., National Jewish Medical and Research Center, Denver, red fire ants have encroached on the territory of the black fire ant in northern portions of Mississippi and Alabama, and now extend over 310 million acres over 12 states including New Mexico, Arizona and California.
"Within even a few weeks' time, 50 percent of persons in fire ant-endemic areas will be stung," Dr. Weber said. "The sting of a fire ant causes an immediate burning sensation due to toxic oily alkaloids in the venom. Pustules develop 18 to 24 hours after the stings, and the lesions may persist for a week and may cause scarring. The ant can sting repeatedly, resulting in a ring of pustules.
Treatment for fire ant stings is aimed at preventing secondary bacterial infection, which may occur if the pustule is scratched or broken. Blisters should be cleaned with soap and water to prevent secondary infection. Topical corticosteroid ointments and oral antihistamines may relieve the itching associated with these reactions.
"Anaphylaxis occurs in 1 percent to 16 percent of fire ant stings, and is attributable to the soluble proteins comprising 1 percent of the venom weight. More than 80 deaths had been attributed to fire ants by 1998," Dr. Weber said.
"Kissing bugs"
Although allergies to stinging insects are more common, according to John E. Moffitt, M.D., also an allergist at University of Mississippi Medical Center, Jackson, allergic reactions have been reported following many different types of arthropod bites, primarily Triatoma, flies, or mosquitoes.
"In the western and southwestern United States, Triatoma bites appear to be an important cause of anaphylaxis," Dr. Moffitt said. "Since their bite is usually painless and inflicted during sleep, the person may not be aware of the bite, and resulting allergic reactions may not be diagnosed or mistakenly attributed to other causes. The lack of commercial antigen limits diagnostic and treatment capabilities."
Management of Triatoma allergy is similar to that of anaphylaxis due to bites and stings of other insects for which no immunotherapy is available.
"Personal protection measures from kissing bugs involve avoidance where possible and use of pesticides approved for indoor use. Prevention of bug entry into homes may involve outdoor light management and sealing entry points around the home," said Dr. Moffitt.
"Blankets and sheets should be examined for Triatoma. Removal of piles of paper, clothing and other clutter from the bedroom may reduce hiding places. Since the bugs rarely bite covered skin, wearing of pajamas with long legs and sleeves is recommended. Some also recommend the use of insect repellants on exposed skin before sleep," he said.
Mosquitoes
Most people who get mosquito bites develop small, itchy skin reactions that last for a few hours or a few days. These reactions are caused by the saliva the mosquito injects into the skin at the time of the bite, according to F. Estelle R. Simons, M.D., professor and head, Division of Allergy & Clinical Immunology, University of Manitoba, Winnipeg, Canada.
"Increased IgE antibody to mosquito saliva develops in people with mosquito allergy, causing more severe reactions at the sites of the mosquito bites," said Dr. Simons. "These allergic reactions, such as a large red swelling, a skin blister, bruise, or hives, may last for a week or more. Rarely, severe acute allergic reactions involving many body systems may occur."
Steps to prevent mosquito allergy include avoiding mosquito-infested areas, wearing protective clothing, eliminating standing water on surrounding property, keeping window and door screens in good condition, avoiding scented products and using mosquito repellants.
"Personal repellants containing DEET work best. Repellants containing more than 10 percent DEET should not be used on infants or children under age 6 years," said Dr. Simons.
About ACAAI
The American College of Allergy, Asthma and Immunology is a professional medical organization comprising 4,300 qualified allergists-immunologists and related health care professionals. The College is dedicated to the clinical practice of allergy, asthma and immunology through education and research to promote the highest quality of patient care.
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