For most individuals, insect stings cause immediate local reactions at the sting site and produce a temporary discomfort of redness, pain, itching and swelling lasting only a few hours. A large local reaction may be more painful with itching and swelling at the sting site and in surrounding areas that may last for a few days. For these latter two reactions, local skin care and occasionally oral antihistamines, corticosteroids and perhaps antibiotics may be required for relief. These reactions, however, do not necessitate venom skin testing and/or desensitization injections with venom extracts.
In a small number of people, a severe allergic reaction involving the entire body, remote from the sting site, can occur very rapidly. In children less than 16, a generalized hive reaction confined to the skin does not necessarily require skin testing or desensitization injections. However in individuals 16 and older, this same reaction does require venom skin testing evaluation.
A very severe reaction called anaphylaxis may occur causing symptoms of dizziness, weakness, stomach pains, diarrhea, wheezing, difficulty breathing and hives. Because blood pressure may quickly fall during these reactions, immediate medical attention is required. Since this type of reaction is potentially fatal and effective injection therapy is available, all individuals with a history of insect sting anaphylaxis must undergo insect venom testing.