Onset of bite symptoms (redness, pain, swelling) and a spider is seen in close proximity.
Types of Spider Bites
1. 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.
2. 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, muscle pain can occur (but no life-threatening symptoms).
3. Non-dangerous 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.
WHEN TO CALL YOUR DOCTOR FOR SPIDER BITE
Call 911 Now (your child may need an ambulance)If
Difficulty breathing or swallowing.
See More Appropriate Topic (instead of this one) If
Not a spider bite, see INSECT BITE. (To go directly to this topic, click on the link following this document.)
Call Your Doctor Now (night or day)If
Your child looks or acts very sick.
Any black widow spider bite.
FIRST AID for Black Widow Spider Bites: Apply an ice cube or ice pack to the bite for 20 minutes to reduce the spread of the venom (no tourniquet).
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 9am and 4pm) If
You think your child needs to be seen.
Bite starts to look bad (e.g. skin damage, blister or purplish - not just swelling).
Bite pain persists for more than 2 days.
Call Your Doctor During Weekday Office Hours If
You have other questions or concerns.
Parent Care at Home If
Non-serious spider bite and you don't think your child needs to be seen.
HOME CARE ADVICE FOR NONDANGEROUS SPIDER BITES
1.Cleansing: Wash the bite thoroughly with soap and water.
2. 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.
3. Pain Medicine: Give acetaminophen (e.g. Tylenol) or ibuprofen as needed for pain.
4. Expected Course: Some swelling and pain for 1 to 2 days. It shouldn't be any worse than a bee sting.
5. Call Your Doctor If:
Severe bite pain persists for more than 2 hours after pain medicine.
Abdominal pains or muscle spasms occur.
Local pain lasts more than 2 days (48 hours).
Bite begins to look infected.
Your child becomes worse or develops any of the "Call Your Doctor" symptoms.
Lucile Packard Children's Hospital is located in Palo Alto, adjacent to Stanford University Hospital, approximately 20 miles north of San Jose, CA and 40 miles south of San Francisco.
