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Insect Bites and Stings and Spider Bites

Overview

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

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

Examples of problems that are more serious include:

  • A severe allergic reaction (anaphylaxis, Opens dialog). These reactions aren't common. But they can be life-threatening and require emergency care. They may cause:
    • Shock, Opens dialog. This can occur if the circulatory system can't get enough blood to the vital organs.
    • Coughing, wheezing, trouble breathing, or a 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).
    • Lightheadedness, Opens dialog and confusion, Opens dialog.
    • Belly pain, nausea, vomiting, or diarrhea.
    • Raised, red, itchy bumps called hives, Opens dialog and red skin. These symptoms often occur with other symptoms of a severe reaction.
  • A toxic reaction to a single sting or bite. Spiders or insects that may cause this include:
  • A toxic reaction to multiple stings or bites from a bee, wasp, or fire ant.
    • A bee leaves its stinger behind and then dies after stinging. Africanized honeybees, the so-called killer bees, Opens dialog, are more aggressive than common honeybees. They often attack together in great numbers. Reaction to bee stings can range from minor skin swelling and redness to a serious allergic reaction.
    • Wasps, including hornets and yellow jackets, Opens dialog, can sting over and over.
    • A fire ant is a wingless insect. It 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 large skin reaction with swelling and redness that spreads away from the site of the bite or sting. It may be as large as swelling across two major joints, such as from the elbow to the shoulder.
  • A skin infection, Opens dialog at the site of the bite or sting.
  • Serum sickness, Opens dialog. This is a reaction to the medicines (antiserum) used to treat a bite or sting. It may cause hives and flu-like symptoms, such as a fever, muscle aches, or a headache about 3 to 21 days after the use of antiserum.
  • A virus infection. Infected mosquitoes can spread the West Nile virus, Opens dialog to people, causing an inflammation of the brain (encephalitis, Opens dialog).
  • A parasite infection. Infected mosquitoes can spread malaria, Opens dialog.

Common insects and spiders

Insects that cause mild reactions include:

  • Bedbugs.
  • Kissing bugs.
  • Chiggers.
  • Fleas.
  • Flies.
  • Mites.
  • Mosquitoes.
  • Nonpoisonous spiders.
  • Ticks.
  • Scabies.
  • Lice.

Some insects are more likely than others to cause allergic or toxic reactions.

  • A bee leaves its stinger behind and then dies after stinging. Africanized honeybees, the so-called killer bees, Opens dialog, are more aggressive than common honeybees and often attack together in great numbers. Reaction to bee stings can range from minor skin swelling and redness to a serious allergic reaction.
  • Wasps, including hornets and yellow jackets, can sting over and over. Yellow jackets cause the greatest number of allergic reactions.
  • A fire ant attaches to a person by biting with its jaws. Then, pivoting its head, it stings from its abdomen in a circular pattern at multiple sites.
Information about Insect Bites and Stings and Spider Bites

Current as of: July 31, 2024

Author: Ignite Healthwise, LLC Staff

Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

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