Prather Pediatric and Allergy Center - Ask Doctor Brent

Printer Friendly Version

Title: Fire Ant Allergy and other Stinging Insects



Fire ants were imported to the United States from South America at the turn of the century. They originally came by ship and entered through Mobile, Alabama. By 1950 they had reached nine southern states and by the year 2000 they are expected to have reached about 1/4 of the entire land mass of the United States. The fire ant has mutated and become much more aggressive and much more tolerant of temperature extremes so that it has expanded beyond the warm Southeastern United States particularly in the last ten years. In the past, there was only one queen ant per mound but now there are several queens per mound which allows them to multiply much more rapidly. They also can now tolerate temperatures below 10 degrees and survive winters which has allowed them to migrate all the way up to just south of Washington, D.C. They essentially have no natural enemies and they have become intolerant to several commonly used pesticides used in the past.

One of the major problems associated with fire ants besides all of the nuisance problems they cause with mounds everywhere and farm damage, etc., is their tremendous ability to cause allergic reactions. About 1 in 100 persons stung by fire ants will have a full blown anaphylactic reaction. This is an explosive life-threatening reaction involving wheezing, tightness in the throat, hives and drop in blood pressure. This can occur with as little as one ant bite. In one recent study polling about 29,000 doctors there were 32 deaths from fire ant sting anaphylaxis which occurred in children from 16 months of age up to adults 65. They involved primarily patients who had been stung less than five times.

Other complications from fire ants which are less life- threatening but certainly a nuisance, include the local re-actions which can range from a small red bump to a sterile pustule to a very large painful local reaction which sometimes gets infected. The immediate measures which are always important are to wash the skin with soap and water and then follow this with alcohol to try and dry it and get off any venom from the surface of the skin. For a large allergic reaction, antihistamines are in order such as large doses of Benadryl or any other potent antihistamine; Cortisone creams also help decrease the local reaction.

Treatment for anaphylaxis involves the above plus emergency treatment including an immediate Adrenalin injection and possibly a second one a few minutes later. Also, a large dose of antihistamine, preferably liquid to get into the body as quickly as possible. Also, routine treatment for shock including IV fluids and other agents as needed to control the anaphylactic symptoms.

For Prevention of life threatening anaphylactic reactions, it is highly recommended that people who have had large local reactions or have ever had anaphylactic reactions receive or carry an Adrenalin emergency kit. This can be prescribed by their doctor as EpiPen, EpiPen Jr., or Ana-Kit. Patients who have truly had a life-threatening anaphylactic reaction should discuss with their doctor the option of taking allergy shots to desensitize to the fire ant. This is also important for patients allergic to stinging insects such as hornets, yellow-jackets, wasps and bees. For ants, the only available extract is a crushed whole body extract which is not quite as effective as the pure venom extract available for the other stinging insects. Nevertheless, several good, large studies have shown that proper desensitization with the ant extract does provide good protection. It is a time consuming and expensive process which takes patience, but for a patient who is likely to be re-stung and is at high risk, it is certainly important to consider desensitization as an option beyond just carrying Adrenalin.

Doctors who specialize in fire ant allergy and other stinging insects are concerned that there is a major increase in fire ant stings nationwide and that the problem in the future will just grow larger. Hopefully, we will soon have a pure venom ant extract avail-able for quicker desensitization.