Spider Bites (Including Black Widow and Brown Recluse)

  • Medical Author:
    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

  • Medical Editor: William C. Shiel Jr., MD, FACP, FACR
    William C. Shiel Jr., MD, FACP, FACR

    William C. Shiel Jr., MD, FACP, FACR

    Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

Black Widow vs. Brown Recluse Slideshow Pictures

Spider Bites

Spider Bite Remedies

What should you do if you are bitten by a spider?

  • Wash the site of the spider bite well with soap and water.
  • Apply a cool compress or ice pack over the spider bite location.
  • Over-the-counter pain relievers may be used to relieve symptoms. (Remember, do not give aspirin to children; use acetaminophen or ibuprofen instead).
  • Call the doctor or seek emergency treatment if the victim is a young child, if you think the bite may have been from a black widow or brown recluse spider, if any signs of an allergic reaction occur, if the bite area becomes infected, or if the victim develops a rash or severe illness.
  • If possible, retrieve the spider and bring it with you to the health care practitioner so that it can be definitively identified.
  • A tetanus booster shot may be necessary, depending upon the date of the patient's last immunization.

Quick GuideSpider Pictures Slideshow: Black Widow vs. Brown Recluse

Spider Pictures Slideshow: Black Widow vs. Brown Recluse

Spider bites facts

  • Most spiders are harmless; the two exceptions in the U.S. are the black widow and brown recluse spiders.
  • Spider bites are actually rare occurrences, and most presumed cases of spider bites are likely due to another condition that mimics the symptoms of a spider bite.
  • Bites from most (non-poisonous) spiders cause local redness, irritation, and pain that usually can be treated at home.
  • Always seek emergency medical care for a presumed black widow or brown recluse spider bite.

What are the symptoms of spider bites?

Bites from most (non-poisonous) spiders cause local redness, irritation, and pain that usually can be treated at home using an over-the-counter pain reliever along with application of cooling packs or a wet cloth to relieve swelling. These local reactions usually resolve without treatment over a period of 7-10 days. Rarely, an individual can have an allergic reaction to a spider bite, even to a bite from a non-poisonous spider, but allergic reactions are more likely to be due to contact with a spider than from a spider bite.

Black widow spider bite symptoms

A black widow spider bite is said to feel like a pinprick, although victims may not realize that they have been bitten. Sometimes double fang marks may be seen at the location of the bite. The most common localized symptoms of a black widow spider bite are immediate pain, burning, swelling, and redness.

Picture of the underside of a black widow spider and an egg sack
Picture of the underside of a black widow spider and an egg sack
Picture of a top view of a black widow spider
Picture of a top view of a black widow spider

Brown recluse spider bite symptoms

The bite of a brown recluse spider leads to a mild stinging, followed by local redness and severe pain that usually develops within eight hours but may occur later. Some reports of brown recluse bites describe a blue or purple area around the bite, surrounded by a whitish ring and large red outer ring in a "bull's eye" pattern. A fluid-filled blister forms at the site and then sloughs off to reveal a deep ulcer that may turn black.

Picture of a brown recluse spider. Note the violin pattern on the cephalothorax and light-colored hairless abdomen.
Picture of a brown recluse spider. Note the violin pattern on the cephalothorax and light-colored hairless abdomen.
Picture of a brown recluse spider
Picture of a brown recluse spider
Picture of a brown recluse spider head close-up
Picture of a brown recluse spider head close-up

Generalized symptoms of bites from black widow and brown recluse spiders may include:

While black widow spider bites are hardly ever fatal, rare deaths have occurred from brown recluse spider bites and are more common in children than in adults.

If a spider was not observed inflicting the bite, it is difficult if not impossible to determine whether a spider bite occurred, since many conditions of the skin may produce the same symptoms as a spider bite. Streptococcal and Staphylococcal infections, early lesions of herpes simplex or zoster, burns, stings or bites from other arthropods or insects (including fleas, bedbugs, mosquitos, biting flies, ants, and ticks), thorn injury, and early Lyme disease all may be characterized by skin findings similar to those from a spider bite. Spiders rarely bite people, and only if threatened. People often thing they have spider bites when the irritation is from another cause.

Medically Reviewed by a Doctor on 5/7/2015

Subscribe to MedicineNet's Skin Care & Conditions Newsletter

By clicking Submit, I agree to the MedicineNet's Terms & Conditions & Privacy Policy and understand that I may opt out of MedicineNet's subscriptions at any time.

VIEW PATIENT COMMENTS
  • Spider Bites - Type of Spider and Reaction

    What type of spider bit you, and did you have a reaction?

    Post View 31 Comments
  • Spider Bites (Black Widow, Brown Recluse) - Treatments

    What was the treatment for your spider bite?

    Post View 12 Comments
  • Spider Bites - Symptoms

    Please describe your symptoms associated with a spider bite.

    Post View 16 Comments
  • Spider Bites - Brown Recluse

    Have you or someone you know ever been bitten by a brown recluse spider? Please share your story.

    Post View 5 Comments
  • Spider Bites - Black Widow

    Have you or someone you know ever been bitten by a black widow spider? Describe the experience.

    Post View 3 Comments

Health Solutions From Our Sponsors