The brown widow spider, or Latrodectus geometricus, is one of five widow spider species found in the United States. More than 30,000 species of spiders exist, but only a few can inflict a serious bite and produce venom harmful to humans, according to Dr. James H. Diaz and colleagues in a March 2007 article in the journal American Family Physician. The bite of a brown widow spider usually causes only minor problems, but in rare cases brown widow spider bite symptoms can be serious.
Localized Pain and Redness
The two main effects of a bite from a brown widow spider are pain and redness at the site of the bite, says the Center for Invasive Species Research at the University of California, Riverside. You may feel a burning pain and itchiness at the site of the bite, and small bumps might form in the reddened area of the skin.
The pain might be severe. Professor Jerome Goddard and colleagues, in a report on a rare case of a serious brown widow spider bite published in the 2008 Southern Medical Journal, noted that 10 minutes after being bitten, a 20-year-old man arrived at the hospital with pain, swelling and redness at the site of the bite. The patient, who was bitten in the neck, compared the pain of the bite with being hit with something "like a sledgehammer.”
Radiating Pain and Redness
Professor Godard said that a half hour after arriving at the hospital, the young man experienced increasing pain in his neck and pain expanding into his upper body. In the first reported case of envenomation by a brown widow spider in Venezuela, a woman suffered a bite in the area of her shoulder blade. Professor Demetrio Kiriakos and colleagues described the progression of her symptoms in a case study published in the Review of the Brazilian Society of Tropical Medicine. Four hours after being bitten, the patient felt moderately intense burning pain in the area of the bite. She also experienced paresthesia--an itching or tingling sensation--and redness that extended from her shoulder blade into her entire arm.
Headache and Nausea
You may develop a headache after a bite from a brown widow spider. Professor Kiriakos said that four hours after being bitten, the Venezuelan woman woke up with a steady, intense headache. Professor Godard said that a half hour after arriving at the hospital, the young man in the U.S. experienced headache, nausea, vomiting and cramps.
After a bite from a brown widow spider, a person may experience involuntary muscle contractions. The young man who was bitten in the neck began to experience those contractions in his pectoral muscles 40 minutes after the bite. He continued to have contractions in the pectoral and quadriceps muscles six hours after the bite. The Venezuelan woman experienced generalized muscle contractions and rigidity, and cramps in her arms and legs.
- "American Family Physicians"; Common Spider Bites; James H.. Diaz, M.D. et al.; March 2007
- University of California Statewid Integrated Pest Management Program
- "Southern Medical Journal"; Severe Reaction from Envenomation by the Brown Widow Spider, Latrodectus geometricus
- "Revista da Sociedade Brasileira de Medicina Tropical"; First case of human latrodectism in Venezuela; Demetrio Kiriakos, et al.; March/April 2008
- "Journal of Venomous Animals and Toxins including Tropical Diseases"; Envenomation caused by Latrodectus geometricus in S&atilde;o Paulo state, Brazil: a case report; Ricardo Almeida, et al.; 2009