INSECT ALLERGIES: Entomology is the field of science that studies insects. The insects important to the allergist represent only a few of the over 16,000 species in North America, making up the order Hymenoptera.
These stinging Hymenoptera insects do have some positive features, being effective pollinators of plant life and predators of a wide variety of pest species. Insects with the capacity to elicit an allergic reaction include yellow jacket, yellow hornet, white-faced hornet, paper wasp and honeybee.
The yellow jacket is the most aggressive of the flying insects, scavenging for meats and sweets, and nests in and around homes. Swatting at insects or bothering their nests will increase your chance of being stung.
You may have noticed that it is usually one individual amongst a group of people who is attacked by a swarm of insects. This is because the first stinging insect releases a signal that alerts his mates to the location of his prey.
Allergic reactions are the result of a specific immune response to the venom injected into the skin. Previous venom exposure is necessary for one to become sensitized, therefore, people can almost always recall a well tolerated sting in the past. Large local swelling and discomfort at the site of a sting is a normal response to the toxins within the venom and should not be confused with an allergic reaction.
Symptoms of an allergic reaction can be limited to the skin as hives or involve multiple organs, referred to as anaphylaxas (dizziness, weakness, swelling of nose, lips, tongue and throat, nausea, stomach cramps, breathlessness, or loss of consciousness). The allergic reaction usually begins within minutes, but can be delayed in rare situations for 20 minutes or more.
Initial treatment depends on the nature of the reaction. The non-allergic local reaction should subside uneventfully over 48 hours, but on occasion will require the application of ice, elevation if possible, and rarely, oral corticosteroids. Once the reaction is no longer local, i.e. swelling at distant sites from the sting or other anaphylactic symptoms, emergency help should be sought. An antihistamine will reduce the swelling and itching of hives, but do little for the more critical organ involvement (respiratory, heart and vascular). In an Emergency Room, epinephrine (adrenaline) will be given immediately to slow or stop the reaction. In some cases, further therapy with intravenous fluids, oxygen and medications will be necessary.