Insect bites and stings
First aid: Insect bites and stings
Signs and symptoms of an insect bite result from the injection of venom or other substances into your skin. The venom causes pain and sometimes triggers an allergic reaction. The severity of the reaction depends on your sensitivity to the insect venom or substance and whether you've been stung or bitten more than once.
Most reactions to insect bites are mild, causing little more than an annoying itching or stinging sensation and mild swelling that disappear within a day or so. A delayed reaction may cause fever, hives, painful joints and swollen glands. You might experience both the immediate and the delayed reactions from the same insect bite or sting. Only a small percentage of people develop severe reactions (anaphylaxis) to insect venom. Signs and symptoms of a severe reaction include:
Bites from bees, wasps, hornets, yellow jackets and fire ants are typically the most troublesome. Bites from mosquitoes, ticks, biting flies, ants, scorpions and some spiders also can cause reactions. Scorpion and ant bites can be very severe. Although rare, some insects also carry disease such as West Nile virus or Lyme disease.
For mild reactions
Allergic reactions may include mild nausea and intestinal cramps, diarrhea, or swelling larger than 4 inches (about 10 centimeters) in diameter at the site, bigger than the size of a baseball. See your doctor promptly if you experience any of these signs and symptoms.
For severe reactions
Take these actions immediately while waiting with an affected person for medical help:
If your doctor has prescribed an autoinjector of epinephrine, read the instructions before a problem develops and also have your household members read them.
Last Updated: 2012-03-01
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