font size


Spider Bites
(Including Black Widow and Brown Recluse)

Medical Author:
Medical Editor:

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 1/8/2014

Patient Comments

Viewers share their comments

Spider Bites - Type of Spider and Reaction Question: What type of spider bit you, and did you have a reaction?
Spider Bites (Black Widow, Brown Recluse) - Treatments Question: What was the treatment for your spider bite?
Spider Bites - Symptoms Question: Please describe your symptoms associated with a spider bite.
Spider Bites - Brown Recluse Question: Have you or someone you know ever been bitten by a brown recluse spider? Please share your story.
Spider Bites - Black Widow Question: Have you or someone you know ever been bitten by a black widow spider? Describe the experience.
Source: MedicineNet.com
http://www.medicinenet.com/spider_bites_black_widow_and_brown_recluse/article.htm

Women's Health

Find out what women really need.

advertisement
advertisement
Use Pill Finder Find it Now See Interactions

Pill Identifier on RxList

  • quick, easy,
    pill identification

Find a Local Pharmacy

  • including 24 hour, pharmacies

Interaction Checker

  • Check potential drug interactions
Search the Medical Dictionary for Health Definitions & Medical Abbreviations