Every year 500,000 people present to the emergency room with reactions to insect stings and bites. The severity of these reactions is quite variable. Unfortunately, 0.5% of these reactions are life threatening and result in about 40 deaths per year in the United States. In the south/southeast, the most common insect responsible for a severe allergic reaction is the fire ant. The fire ant arrived in the United States on produce and infected nursery stock from South America that was shipped through the port of Mobile, Alabama around 1918. Currently, the fire ant infests 14 southern states, from California to Florida and extending up into Maryland.
The fire ant species found in the United States are the black imported fire ant, Solenopsis richteri and the red imported fire ant, Solenopsis invicta; with the red fire ant being the predominant species. Unlike the fire ant, common ants such as carpenter ants and sugar ants do not sting; therefore they are not associated with severe allergic reactions.
In areas endemic with fire ant, the chance of being bitten each year by a fire ant is reported to be 30-60% a year. The numbers tend to be higher in children and young adults. A normal reaction to a fire ant bite is a localized itchy lump. Usually, a small pustule forms about 8 to 24 hours later. It is important to avoid breaking the pustule in order to keep it from becoming infected. The therapy is keeping the area clean, an oral antihistamine (cetirizine, fexofenadine, diphenhydramine) to help with the itching/swelling and time. Sometimes the area can get quite red and swollen which can be treated with either topical or oral steroids to reduce the swelling.
Unfortunately, some of us develop a severe systemic allergic reaction to the fire ant sting. This includes a wide range of symptoms: diffuse welts or hives over the body, swelling of the tongue and lip, hoarseness, chest tightness or difficulty breathing, feeling faint, cramping abdominal pain, and “blacking out.” Immediate medical attention is needed for any of these symptoms. After being treated for the acute reaction, the person must seek follow-up care and evaluation with an Allergist. This is because the chance of a similar severe allergic reaction if one is bitten again is 60 percent. Quite High!!!
The most effective long-term therapy for a severe insect sting reaction is “allergy shots” (immunotherapy). If the person is placed on allergy shots, the chance of a severe reaction is less than 5 percent. Immunotherapy can be lifesaving!!! In addition, the person should be prescribed and trained in the use of injectable epinephrine. Other recommendations include:
1. Avoid open-faced sandals or walking barefoot.
2. Aggressive treatment of one’s lawn with chemical controls to decrease ant mounds.
3. If gardening, one needs to wear gloves and protective clothing.
4. Keep injectable epinephrine and an antihistamine with you at all times.
5. If one experiences a severe reaction, it’s important for you to see an Allergist.
To learn more about fire ant allergy, consult your trusted Allergy Partners physician or visit allergyparntners.com
Dr. Kenneth Myers
Allergy Partners of Coastal Carolina