Spider Bite
Main Symptoms
- Bite from a spider seen on the skin
- Onset of bite symptoms (redness, pain, swelling) and a spider is seen in close proximity
Types of Spider Bites
- Black Widow Spider Bite
- A shiny, jet-black spider with long legs (total size 1 inch)
- A red (or orange) hourglass-shaped marking on its under-side
- Causes immediate local mild pain, swelling and occasionally 2 fang marks
- Severe muscle cramps are present by 1 to 6 hours, and 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
- Brown Recluse Spider Bite
- A brown spider with long legs (total size 1/2 inch)
- A dark violin-shaped marking on top of its head
- Causes local pain and delayed blister formation in 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
- Systemic symptoms such as fever, vomiting, myalgias can occur (but no life-threatening symptoms)
- Nondangerous Spider Bites
- More than 50 spiders in the U.S. have venom and can cause local, nonserious reactions.
- The bites are painful and mildly swollen for 1 or 2 days (much like a bee sting).
- Most single, unexplained, tender bites that occur during the night are due to spiders.
See More Appropriate Topic
- If not a spider bite, see Insect Bite
Call 911 Now (your child may need an ambulance) If
- Difficulty breathing or swallowing
Call Your Doctor Now (night or day) If
-
- Your child looks or acts very sick
- Any black widow spider bite
- Abdominal pain, chest tightness or other muscle cramps
- Bite pain is severe
- Bite looks infected (red streaking from the bite area, yellow drainage) (Note: infection doesn’t start until at least 24-48 hours after the bite. Any redness in the first 24 hours is due to venom)
Call Your Doctor Within 24 Hours (between 9 and 4) If
- You think your child needs to be seen
- Bite pain persists > 2 days
- NOTE: Since brown recluse spiders are hard to identify, bring the spider along in a jar
Call Your Doctor During Weekday Office Hours If
- You have other questions or concerns
Parent Care at Home
- Nonserious spider bite and you don’t think your child needs to be seen
Home Care Advice for Nondangerous Spider Bites
- Cleansing: Wash the bite thoroughly with soap and water
- Meat Tenderizer: Rub the bite area with a cotton ball soaked in a meat tenderizer solution for 20 minutes. (Exception: avoid if near the eye.) If not available, apply an ice cube for 20 minutes
- Pain Medicine: Give acetaminophen or ibuprofen as needed for pain
- Expected Course: Some swelling and pain for 1 to 2 days. It shouldn’t be any worse than a bee sting
- Call Your Doctor If
- Severe bite pain persists > 2 hours after pain medicine
- Abdominal pains or muscle spasms occur
- Local pain lasts > 2 days (48 hours)
- Bite begins to look infected
- Your child becomes worse or develops any of the “Call Your Doctor” symptoms