One to two million Americans have allergic reactions to insect venom (i.e. fire ant, honey bee, wasp), which causes venom allergies. These allergic reactions may present as burning, itching or swelling at the site of the sting, generalized welts or hives, itchy eyes, nose and throat, nose congestion, tightness in the throat or chest, coughing; wheezing, dizziness, faintness, nausea and vomiting. Documented death, as a result of reactions from venom allergies, or stinging insects, occurs in about forty persons per year. However, the numbers are probably four to five times greater since these fatalities may occur without reporting that they are associated with a known insect sting.
What is Venom Immunotherapy?
Purified insect venoms are available for individuals with allergy to stinging insect(s). Insect venom desensitization may significantly decrease the risk for severe allergic reactions in previously allergic individuals. Extract for the imported fire ant immunotherapy is derived from the whole ant.
Patients for Whom Immunotherapy is Recommended
How Immunotherapy Works
The protective mechanisms are: decrease in skin sensitizing antibody (IgE) which causes the allergic reaction, increase in the blocking antibody (IgG), and decreased allergic cellular responses, all of which actively block the allergic reaction.
How Treatment is Given for Venom Allergies
The selection of venom immunotherapy is based on the patient’s history, allergy skin tests and/or RAST blood tests. Increasing doses of venom are given initially one to two times weekly for approximately 6-12 weeks.
The dose intervals then gradually increase to every four weeks. Injections are given every four weeks for three to five years or longer.
Want to Learn More?
Possible Immunotherapy Side Effects
Immunotherapy should be given at a medical facility under the orders of a physician. Occasionally, allergic reactions occur which require immediate medical therapy. Since most of the reactions occur within 30 minutes, the patient is asked to stay in the medical facility for this length of time and be checked before leaving. The allergic reactions may present as: burning, itching or swelling at the site of the injection(s), generalized welts or hives, itchy eyes, nose and throat, nose congestion, tightness in the throat or chest, coughing, wheezing, lightheadedness, faintness, nausea and vomiting. Rarely, severe and lift-threatening anaphylaxis (faintness, nausea, wheezing, welts) and death occur for people that have been treated for venom allergies.
Venom Allergies: Benefits and Alternatives
The venom-treated patient has a significantly lower rate of reaction re-occurrence after a challenge sting (these are usually mild and consist of hives). Alternatives to venom immunotherapy are avoidance of stinging insects, and carrying epinephrine auto-injectors*.
*Epinephrine Auto-injector should be carried at all times, even if patient is on immunotherapy.
Once maintenance (top dose) immunotherapy is achieved, there is much less need for such a precaution. However, it is still recommended that an adrenaline-containing syringe (EpiPen) be readily available to the patient to combat sever venom allergies.