Overview

What Are Spider Bites?

Spider bites happen when a spider bites someone’s skin. Most spider bites don't go all the way through skin, so they usually cause only mild reactions. But a bite from a black widow spider or brown recluse spider can cause serious reactions and needs medical care right away. Allergic reactions to spider bites can happen but are rare.

Signs & Symptoms

What Are the Signs & Symptoms of a Spider Bite?

The signs and symptoms of a spider bite depend on the type of spider and whether the person has a spider bite allergy.

Brown Recluse Spider Bites

• swelling or redness around the bite
• pain around the bite within 2–8 hours
• blisters around the bite
• rarely, chills, fever, nausea, rash, body aches, and dark urine (pee)
• some bites can become dark in the center

Black Widow Spider Bites

• either no visible bite or very mild pain at the bite
• painful muscle cramps starting a few hours after the bite
• a firm and painful belly
• nausea and vomiting
• shakiness and weakness
• sweating
• headache
• rarely, trouble breathing

Allergic Reactions to Spider Bites 

• swelling of the face or mouth
• trouble swallowing or speaking
• chest tightness, wheezing, or trouble breathing

If someone in your family might have a bite from a brown recluse spider or black widow spider, visit the National Poison Control Center online or call 800-222-1222. Because spider bites contain venom, which is a type of poison, poison control is an expert resource. It's available for free, 24 hours a day.

Prevention

What Can Help Prevent Spider Bites?

• Be careful in garages and attics and around woodpiles. Make sure they are free of spider webs.
• Wear gloves when gardening, cleaning out the garage, or working in outdoor spaces such as woodpiles.
• Dress kids in long sleeves and pants when they're active around garages, attics, woodpiles, etc.
• Keep firewood outside the house to avoid bringing spiders inside.
• Shake out shoes and gardening gloves stored in a garage, shed, basement, attic, or mudroom before putting them on.

Treatment & Care

How is a Spider Bite Treated?

If your child has been bitten by a spider:

• Wash the area with soap and water.
• Put an ice pack wrapped in a thin towel or a cool wet cloth on the bite area to relieve pain and swelling.
• Watch for redness, swelling, or other signs of the bite getting worse or infected.
• Call the doctor to make sure your child is up to date on their tetanus vaccine.

When Should I Get Medical Care Right Away?

If you think your child was bitten by a brown recluse spider or black widow spider, see a doctor right away even if there are no symptoms. Early treatment can help ease symptoms.

Also call the doctor if your child:

• has any signs of an allergic reaction
• develops any kind of rash after a bite
• has severe pain or cramping
• develops signs of an infection (increasing redness, pain, swelling, warmth, or pus)