Black widow spider

This poisoning is from a bite by a black widow spider.

Where Found  

Black widows are found throughout the U.S., but predominantly in the South and West. They are usually found in barns, sheds, stone walls, fences, woodpiles, porch furniture, and other outdoor structures.


  • Body as a whole       o Pain similar to a pinprick at site of bite       o Numbness (changes to a more numbing pain of the affected area)       o Muscle pain and cramps, especially of the shoulders, back, thighs, abdomen, or chest       o Increased sweating       o Increased salivation  
  • Circulatory       o High blood pressure  
  • Respiratory       o Difficulty breathing  
  • Skin       o Faint redness around bite area       o Mild swelling of bite area       o Itching  
  • Gastrointestinal       o Nausea and/or vomiting  
  • Nervous system       o Muscle weakness       o Restlessness       o Anxiety       o Headache  
  • Reproductive system       o In pregnancy, uterine contractions and premature labor

Home Treatment

Place ice (wrapped in a washcloth or other suitable covering) on the site of the bite for 10 minutes and then off for 10 minutes. Repeat this process. Seek immediate emergency medical treatment.

Before Calling Emergency

Determine the following information:

  • Patient’s age, weight, and condition  
  • Time the bite occurred  
  • Area where the bite occurred  
  • Identity of the spider, if possible

Poison Control, or a local emergency number

They will instruct you if it is necessary to take the patient to the hospital. See Poison Control Centers for telephone numbers and addresses.

If it is necessary to go to the hospital, bring the spider (if safely possible) to the emergency room for identification.

What to expect at the emergency room

Treat the symptoms with a variety of therapies, such as pain medication, muscle relaxants for spasms, anti-hypertension drugs for elevated blood pressure, and in severe cases, antivenin medication.

Expectations (prognosis)

Death in a normally healthy individual is very rare, but is more likely in very small children and elderly victims. Severe symptoms usually resolve within 2-3 days, but milder symptoms may persist for several weeks.

Johns Hopkins patient information

Last revised: December 4, 2012
by Janet G. Derge, M.D.

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.