Insect Bites and Stings and Spider Bites

Insect and spider bites often cause minor swelling, redness, pain, and itching. These mild reactions are common and may last from a few hours to a few days. Home treatment is often all that is needed to relieve the symptoms of a mild reaction to Reference common stinging or biting insects and spiders.

Some people have more severe reactions to bites or stings. Babies and children may be more affected by bites or stings than adults.

Examples of problems that are more serious include:

• A severe allergic reaction (Reference anaphylaxis Opens New Window). Severe allergic reactions are not common but can be life-threatening and require emergency care. Signs or symptoms may include:
  • Reference Shock Opens New Window, which may occur if the circulatory system cannot get enough blood to the vital organs.
  • Coughing, wheezing, trouble breathing, or feeling of fullness in the mouth or throat.
  • Swelling of the lips, tongue, ears, eyelids, palms of the hands, soles of the feet, and mucous membranes (angioedema).
  • Reference Lightheadedness Opens New Window and Reference confusion Opens New Window.
  • Nausea, diarrhea, and stomach cramps.
  • Raised, red, itchy bumps called Reference hives Opens New Window and reddening of the skin. These symptoms often occur with other symptoms of a severe reaction.
• A Reference toxic reaction to a single sting or bite. Spiders or insects that may cause this include:
  • Reference Black widow spider.
  • Reference Brown recluse spider.
  • Reference Scorpion.
  • Reference Puss caterpillar (woolly slug).
• A Reference toxic reaction to multiple stings or bites from a bee, wasp, or fire ant.
  • A Reference bee leaves its stinger behind and then dies after stinging. Africanized honeybees, the so-called Reference killer bees Opens New Window, are more aggressive than common honeybees and often attack together in great numbers.
  • Reference Wasps, including hornets and yellow jackets Opens New Window, can sting over and over.
  • A Reference fire ant attaches to a person by biting with its jaws. Then, pivoting its head, it stings from its belly in a circular pattern at multiple sites.
• A Reference large skin reaction at the site of the bite or sting.
• A Reference skin infection Opens New Window at the site of the bite or sting.
• Reference Serum sickness Opens New Window, a reaction to the medicines (antiserum) used to treat a bite or sting. Serum sickness may cause hives and Reference flu-like symptoms about 3 to 21 days after the use of antiserum.
• A virus infection. Infected mosquitoes can spread the Reference West Nile virus Opens New Window to people, causing an inflammation of the brain (Reference encephalitis Opens New Window). For more information, see the topic Reference West Nile Virus.
• A parasite infection. Infected mosquitoes can spread Reference malaria Opens New Window. For more information, see the topic Reference Malaria.

Reference Check your symptoms to decide if and when you should see a doctor.

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This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Reference Terms of Use. Reference How this information was developed to help you make better health decisions.