• Spider Bites

    Few spiders in the United States can cause serious illness or death. The bites of harmless spiders cause reactions similar to that of a bee sting (e.g., swelling, redness, and stinging or pain at the site).

    Dangerous spiders that live in the United States include the brown recluse spider (also known as the violin or fiddleback spider) and the black widow spider. The bites of the black widow and brown recluse spiders can, in rare cases, kill a person.

    Signs and Symptoms of Spider Bites

    Signs and symptoms of spider bites depend on the amount of venom injected and the person’s sensitivity to the venom. Most spider bites heal with no adverse effects or scarring. Signs and symptoms of venomous spider bites can seem identical to those of other conditions and therefore can be difficult to recognize. The only way to be certain that a spider has bitten a person is to have witnessed it.

    Emergency Steps


    Check the scene safety, form an initial impression, obtain consent and put on PPE, as appropriate.

    • Rigid shoulder, chest, back or abdominal muscles*
    • Anxiety or restlessness*
    • Headache or dizziness*
    • Excessive sweating*
    • Weakness*
    • Eyelid drooping or swelling*
    • Little or no initial pain; pain developing one plus hours later*
    • Blood-filled blister under skin
    • Target or bullseye pattern increasing in size causing tissue destruction and black scab*
    • Generalized body numbness*
    • Trouble breathing*
    • Seizures*
    • Immediate sharp pinprick pain, then dull pain in bite area
    • Localized pain, tingling, burning or numbness
    • Swelling or redness

    *Note: Signs and symptoms with a * require immediate emergency medical treatment.


    Call 9-1-1 and get equipment if the person requires immediate emergency medical treatment.


    Give Care.

    General Care

    1. Wash area with soap and water.
    2. For harmless spider bite, apply small amount of antibiotic wound ointment, cream or gel if no known allergies or sensitivities.
    3. Apply a cold pack wrapped in a thin, dry towel.
    4. For black widow or brown recluse spider bite, keep area elevated and as still as possible while waiting for EMS to arrive.
    5. For scorpion sting, have person seek immediate medical care.
    6. Continue checking them as appropriate to determine if additional care is needed.
    7. Keep them from getting cold or overheated.
    8. Give care for shock, if necessary.
    9. Position the person as appropriate.
    10. Assist with or administer medication, if needed, according to your level of training.
    11. Reassure them you will help and that EMS has been called (if appropriate).
    12. Watch for changes in condition, including breathing and responsiveness, and give care as appropriate and trained.

    Spider Bite FAQs

    What does a black widow spider look like?

    Widow spiders can be black, brown or red. A black widow spider has a reddish hourglass shape on the underside of its body and is the most venomous of the widow spiders.

    What does a brown recluse spider look like?

    The brown recluse spider has a distinctive violin-shaped pattern on the back of its front body section.

    Where do people encounter black widow spiders, and brown recluse spiders?

    Black widow and brown recluse spiders prefer dark, out-of-the-way places, such as wood, rock and brush piles, dark garages and attics. People are often bitten on their arms and hands when reaching into such places.

    How can I distinguish between a spider bite and other conditions with similar signs and symptoms?

    It can be difficult to recognize a spider bite. The only way to be sure a spider has bitten a person is to see it happen. Bites of black widow spiders can cause an immediate sharp pinprick pain, followed by a dull pain. Bites of brown recluse spiders may be painless at first; after an hour, pain may develop, followed by a blood-filled blister.

    Is it true that applying a tourniquet, cutting the wound, applying suction, applying ice or applying electricity can help to slow the spread of venom throughout the body?

    This is a myth. None of these measures help slow the spread of venom but are likely to cause pain and injury. Seek medical attention as quickly as possible.

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