VENOM & FIREANT TESTING

Venom Testing

Insect venom allergy can develop at any age. It may take several uneventful stings for manifestations to appear. After an initial sting, the immune system of an affected patient may respond by producing IgE antibodies. Any subsequent stings can trigger a systemic inflammatory response. Symptoms typically peak between 24 and 48 hours after the sting.

It is important to correctly identify the culprit insect, as patients can be allergic to one or several species of stinging insects. It is also important to educate patients who work as beekeepers or greenhouse workers, or who participate in outdoor exercise, as their occupations and hobbies put them at increased risk for receiving a sting. Testing can be used to identify the insects to which a patient is sensitized, which will aid in the selection of the most appropriate treatment.

Diagnostic tests should be carried out in all patients with a history of a systemic sting reaction to detect sensitization. As venom immunotherapy (VIT) is indicated in patients with a history of severe systemic reactions and documented sensitization, it is imperative to correctly identify the offending insect.

Fireant Testing

Testing can be used to confirm your fire ant allergy diagnosis. Typically fire ant allergies can be detected with a skin test (scratches and intradermal testing) using ant venom extract.

Fire ants are biting insects that bite the skin and hold on until their stinger injects venom. If you are allergic to fire ants, fire ant venom is the cause of your allergic reaction. Even if you are not allergic, fire ant bites cause a visible reaction on the skin in the form of redness, swelling, pain, and blistering. If you are allergic, the swelling and redness typically affects a larger area and tends to itch as well. Fire ant bites are known to be particularly painful. Part of the reason for this is that fire ants are able to sting their target multiple times in rapid succession by biting down with their jaw while they sting.

Fire ants are commonly found in the southern United States. These territorial insects build nests of dirt in the ground, often on the edges of sidewalks or roads, and usually only become agitated when their nest is disturbed. Nests may be entirely flat or built up as mounds several inches tall. Nests may also be obscured by vegetation, making them difficult to see.

Allergic fire ant reactions tend to be larger than non-allergic reactions. Symptoms include a large area of swelling, redness, pain, and itching localized at the site of the sting. Allergic symptoms occur in around 50% of individuals who are stung by fire ants, and typically present within 12 to 24 hours of being stung.

Allergic reactions to fire ant stings occur in about 1% of the population. Anaphylaxis is a whole-body allergic reaction that occurs in individuals when they’re exposed to something that they’re severely allergic to. Symptoms of anaphylaxis from fire ant stings can include shortness of breath, swelling in the throat or tongue, dizziness, stomach cramps, nausea, or diarrhea. In the most severe cases, blood pressure can drop rapidly, resulting in shock and loss of consciousness. These symptoms present immediately after exposure, and require immediate emergency medical care.

It’s possible to have a severe response to fire ant stings even if you’re not allergic. Symptoms are similar to anaphylaxis, but symptoms are caused by an ‘overdose’ of fire ant venom rather than an allergic response. A toxic reaction to fire ant venom really only occurs when you take on a very large number of stings.