Are You Sick?

Spider Bite

Is this your symptom?

  • Bite from a spider 

Symptoms of a Spider Bite

  • Most spider bites cause local pain, redness and swelling. It's like a bee sting reaction.
  • A few spiders (such as the Black Widow) can cause a more severe reaction.
  • It is helpful to note what the spider looked like, if it was seen on the skin or around you.
  • If you can, capture the spider in a jar with a lid. It will help you identify the spider. Only do this if it does not risk getting another bite.

Cause of Spider Bite Reactions

  • Most spiders have tiny fangs. They inject venom into the skin.
  • The venom is what causes all the symptoms.

Types of Spider Bites

Black Widow Spider Bite

  • A shiny, jet-black spider with long legs. Total size 1 inch (25 mm).
  • A red (or orange) hourglass-shaped marking on its under-side.
  • Causes local pain and swelling right away.
  • Sometimes, you can see 2 fang marks at the bite site.
  • Severe muscle cramps (and stomach cramps) occur within 1 to 6 hours. These last 24 to 48 hours.
  • Rarely causes death. Exception: bitten by several spiders.
  • Note: many are dry bites (no venom) because the fangs are small.
  • The brown widow spider is related to the black widow. It is found in southern US.
  • Brown widow spider bites are treated the same as black widow bites.

Brown Recluse Spider Bite

  • A small brown spider; total size ½ inch (12 mm).
  • A dark violin shaped marking on top of its head.
  • Causes pain at the bite. Blisters form within 4 to 8 hours.
  • The center becomes bluish and depressed (crater-like) over 2 to 3 days.
  • Skin damage may require skin grafting in 10% of cases.
  • Other symptoms such as fever, vomiting, muscle pain can occur. No life-threatening symptoms occur.
  • Brown recluse spiders are hard to identify.

Non-dangerous Spider Bites

  • More than 50 spiders in the U.S. have venom. Their bites cause reactions that are not serious. This includes pain or redness at the bite site.
  • The bites are painful and swollen. This often lasts for 1 or 2 days. They can feel and look like a bee sting.

When to Call for Spider Bite

When to Call for Spider Bite

Call 911 Now

  • Trouble breathing or wheezing
  • Passed out (fainted) or too weak to stand
  • You think you have a life-threatening emergency

Call Doctor or Seek Care Now

  • Fever and bite looks infected (spreading redness)
  • You feel weak or very sick
  • You think you need to be seen, and the problem is urgent

Contact Doctor Within 24 Hours

  • More than 48 hours since the bite and redness gets larger
  • Bite starts to look bad (such as skin damage, blister or purple color)
  • Pain lasts more than 2 days
  • Last tetanus shot was more than 10 years ago
  • You think you need to be seen, but the problem is not urgent

Contact Doctor During Office Hours

  • You have other questions or concerns

Self Care at Home

  • Non-serious spider bite

Call 911 Now

  • Trouble breathing or wheezing
  • Passed out (fainted) or too weak to stand
  • You think you have a life-threatening emergency

Call Doctor or Seek Care Now

  • Fever and bite looks infected (spreading redness)
  • You feel weak or very sick
  • You think you need to be seen, and the problem is urgent

Contact Doctor Within 24 Hours

  • More than 48 hours since the bite and redness gets larger
  • Bite starts to look bad (such as skin damage, blister or purple color)
  • Pain lasts more than 2 days
  • Last tetanus shot was more than 10 years ago
  • You think you need to be seen, but the problem is not urgent

Contact Doctor During Office Hours

  • You have other questions or concerns

Self Care at Home

  • Non-serious spider bite

Care Advice for Non-serious Spider Bites

What You Should Know about Spider Bites:

  • Most spider bites are not dangerous. They look and feel like a bee sting.
  • The main symptoms are pain and redness.
  • Here is some care advice that should help.

Clean the Bite:

  • Wash the bite well with soap and water.

Cold Pack for Pain:

  • For pain or swelling, use a cold pack. You can also use ice wrapped in a wet cloth.
  • Put it on the bite for 20 minutes.
  • Repeat 4 times on the first day, then as needed.
  • Reason: helps the pain.
  • Caution: avoid frostbite by wrapping the ice pack. Do not put ice directly onto the skin.

Pain Medicine:

  • To help with the pain, take an acetaminophen product (such as Tylenol).
  • Another choice is an ibuprofen product (such as Advil). Ibuprofen works well for this type of pain.
  • Use as needed, but do not take more than the maximum recommended dosage as stated on the packet.
  • If you are not sure what to take, ask a pharmacist.

What to Expect:

  • The swelling and pain often last for 1 to 2 days.
  • It should not be any worse than a bee sting.

Call Your Doctor If:

  • Severe bite pain lasts more than 2 hours after pain medicine
  • Stomach pains or muscle spasms occur
  • Bite pain lasts more than 2 days (48 hours)
  • Bite starts to look infected
  • You think you need to be seen
  • Your symptoms get worse

    • Remember! Contact your doctor if you or your child develop any "Contact Your Doctor" symptoms.

    Disclaimer: this health information is for educational purposes only. You, the reader, assume full responsibility for how you choose to use it.

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