Most people who get stung by an insect can develop minor localized redness and swelling at the site of the bite, however for some people, they may experience a much more serious body-wide reaction

Allergic reactions to insect stings are caused by the venom injected. If a person is insect-allergic, after the first sting, their body produces antibodies called Immunoglobulin E (IgE).

If stung again by the same kind of insect, the venom interacts with this specific IgE antibody, triggering the release of substances that can lead to anything from mild to life-threatening or fatal reactions. Patients with insect sting allergies must be trained to recognize and treat severe reactions, and may be candidates for venom immunotherapy, a potentially life-saving treatment option