Overview

Spider bites are usually harmless. Many bites attributed to spiders turn out to have been inflicted by other bugs. Skin infections also have been mistaken for spider bites.

Only a few types of spiders have fangs long enough to penetrate human skin and venom strong enough to severely affect a human being. In the United States, these include the black widow spider and the brown recluse spider.

Black widow spider bites can cause severe abdominal pain or cramping. Brown recluse spider bites can cause a sting or sharp pain, like a bee sting. With severe bites, surrounding skin may die within a few hours. Both types of spiders generally live in undisturbed areas, such as attics or sheds. And they don't bite unless threatened.

May 14, 2016
References
  1. Vetter RS, et al. Approach to the patient with a suspected spider bite: An overview. http://www.uptodate.com/home. Accessed March 8, 2016.
  2. Habif TP. Infestations and bites. In: Clinical Dermatology: A Color Guide to Diagnosis and Therapy. 6th ed. Edinburgh, U.K.; New York, N.Y.: Mosby Elsevier; 2016. https://www.clinicalkey.com. Accessed March 8, 2016.
  3. Spider bites. Merck Manual Professional Version. http://www.merckmanuals.com/professional/SearchResults?query=spider+bites. Accessed March 8, 2016.
  4. Venomous spiders. National Institute for Occupational Safety and Health. http://www.cdc.gov/niosh/topics/spiders. Accessed March 8, 2016.
  5. Vetter RS, et al. Management of widow spider bites. http://www.uptodate.com/home. Accessed March 8, 2016.
  6. Vetter RS, et al. Bites of recluse spiders. http://www.uptodate.com/home. Accessed March 8, 2016.
  7. Brown recluse spider. Occupational Safety and Health Administration. http://www.osha.gov/OshDoc/data_Hurricane_Facts/brown_recluse_spider.pdf. Accessed March 8, 2016.
  8. Diaz JH, et al. Common spider bites. American Family Physician. 2007;75:869.
  9. Claypool DW (expert opinion). Mayo Clinic, Rochester, Minn. Nov. 24, 2014.
  10. Juckett G. Arthropod bites. American Family Physician. 2013;88:841.
  11. Black widow spider. Occupational Safety and Health Administration. http:www.osha.gov/OshDoc/data_Hurricane_Facts/black_widow_spider.pdf. Accessed March 23, 2016.