For most people, getting stung by a wasp or bee is a painful nuisance. But for those allergic to insect venom, it can mean anaphylaxis. Allergic Living asks Dr. Peter Vadas about risks, reactions and protecting yourself.
The insects that cause the majority of life-threatening reactions in North America are: the honeybee, the yellow jacket, the yellow hornet, the white-face hornet, the paper wasp and the fire ant. “Those are the six that we have very good skin-test reagents for, and also the six that we have very good desensitization protocols for,” says Vadas, the director of Allergy and Clinical Immunology at St. Michael’s Hospital in Toronto.
Yellow jackets are the most aggressive, and in the same family as hornets and wasps. This means that if you’re allergic to one, you may be allergic to the others.
The honeybee is a distant relative, with distinct venom proteins, so if that’s your allergen, you aren’t likely to react to the others. Fire ants are native to Florida and Central America, but aren’t a risk farther north.
The first time you’re stung by one of the pesky insects, you won’t have a life-threatening allergic reaction. Your body needs to be exposed to the venom before it recognizes the protein, and begins to create IgE antibodies against it. In fact, you may be stung many times without anaphylaxing, says Vadas.
Those who have the most exposure to the insects are more likely to be stung and therefore more likely to experience sting reactions.
How big is the risk?
The risk in the general population of a sting being life-threatening is about 2 per cent. If you’re having a large reaction at the site of a sting on your body, Vadas says the risk increases slightly, to 5 per cent. With systemic symptoms remote from the sting, such as breathing difficulties or fainting, the risk jumps to 20 to 60 per cent.
When to worry?
The point at which a person becomes at risk of having a life-threatening reaction is different for kids and adults.
If a person younger than 16 years old gets stung and feels the reaction in either his airway (difficulty breathing, chest tightness) or with his blood pressure (dizziness, fainting), he is at risk of having a life-threatening reaction the next time he is stung.
However, if the youth gets swelling (even a large amount), hives, abdominal cramping, diarrhea or itching, he is not considered at risk of a potentially fatal reaction.
In an adult, “anybody who’s had a reaction to a sting that’s remote from the area of the sting is potentially at risk of having a life-threatening reaction,” says Vadas. Hives, breathing difficulties, swelling of lips or tongue, dizziness or fainting are all remote reactions that increase the risk.
Do your best to minimize exposure to the dangerous insects. “Don’t look like a flower; don’t smell like a flower,” says Vadas. This means don’t wear brightly colored clothing or cologne that could attract stinging insects. Also, avoid eating outdoors, and if you must, eat quickly and keep food tightly covered until serving, and use lids on drinks.
Once an allergist has said you are at risk of a life-threatening reaction, you must carry an epinephrine auto-injector at all times and wear medical ID jewelry. If you suspect you have this allergy and haven’t seen an allergist, do so.
Allergy Shots Can Save Lives
If you’ve had an anaphylactic reaction to a sting, you may well prove a suitable candidate for venom immunotherapy. “Venom immunotherapy is 98 per cent effective,” says Vadas.
These allergy shots can desensitize you to the allergen and reduce your risk, usually 20 to 60 per cent, down to 2 per cent, the same level as the general population. New (2011) practice parameters for allergists highly recommend these shots for those at heightened risk of sting anaphylaxis.
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