Is this your child's symptom?
- Bite from a spider
Symptoms of a Spider Bite
- Most spider bites cause local pain, redness and swelling. It's much like a bee sting reaction.
- A few spiders (such as the Black Widow) can cause a more severe reaction.
- Helpful if spider seen on the skin or around the child
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 or 25 mm).
- A red (or orange) hourglass-shaped marking on its under-side.
- Causes immediate local pain and swelling.
- Sometimes, you can see 2 fang marks at the bite site.
- Severe muscle cramps (especially stomach cramps) occur within 1 to 6 hours. These last 24 to 48 hours.
- Rarely causes death. Exception: bitten by several spiders or small child is bitten.
- Note: many are dry bites 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 brown spider with long legs (total size ½ inch or 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. If you can, bring the spider along in a jar.
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 lasts for 1 or 2 days. They can feel and look like a bee sting.
- Some single, unexplained, tender bites that occur during the night are due to spiders.
When to Call for Spider Bite
Call 911 Now
- Trouble breathing or wheezing
- Passed out (fainted) or too weak to stand
- You think your child has a life-threatening emergency
Call Doctor or Seek Care Now
- Fever and bite looks infected (spreading redness)
- Your child looks or acts very sick
- You think your child needs to be seen, and the problem is urgent
Contact Doctor Within 24 Hours
- New redness starts more than 24 hours after the bite. Note: any redness in the first 24 hours is due to venom.
- More than 48 hours since the bite and redness now getting larger
- Bite starts to look bad (such as skin damage, blister or purple color)
- Bite pain lasts more than 2 days
- You think your child needs 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
Seattle Children's Urgent Care Locations
If your child’s illness or injury is life-threatening, call 911.
Care Advice for Non-dangerous Spider Bites
- What You Should Know About Spider Bites:
- Most spider bites 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.
- Pain Medicine:
- To help with the pain, give an acetaminophen product (such as Tylenol).
- Another choice is an ibuprofen product (such as Advil).
- Use as needed.
- What to Expect:
- The swelling and pain lasts 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 cramps occur
- Bite pain lasts more than 2 days (48 hours)
- Bite starts to look infected
- You think your child needs to be seen
- Your child becomes worse
And remember, contact your doctor if your child develops any of the 'Call 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.
Last Reviewed: 06/07/2023
Last Revised: 12/30/2022
Copyright 2000-2023. Schmitt Pediatric Guidelines LLC.