Brown recluse spider

The bite from a brown recluse spider is poisonous.

Poisonous Ingredient

Brown recluse spider venom

Where Found  

  • Most common in the South and Central states, especially in Missouri, Kansas, Arkansas, Louisiana, eastern Texas, and Oklahoma. They have also been reported in several large cities outside this range.  
  • Prefers dark, sheltered areas, such as under porches and in woodpiles.


  • An initial sharp sting or no immediate pain  
  • Pain developing within the first several hours after being bitten, possibly becoming severe  
  • General feeling of discomfort, malaise, or nausea  
  • Formation of an ulcer in the area of the bite  
  • Chills or fever  
  • Sweating  
  • Reddish to purplish color to skin area around bite  
  • Itching  
  • Red or purplish blister

In rare cases:

  • Blood in urine  
  • Jaundice  
  • Kidney failure  
  • Seizures  
  • Coma

Home Treatment

Apply a cold pack, then seek immediate medical attention.

Before Calling Emergency

Before calling emergency, determine the following:

  • Patient’s age, weight, and condition  
  • Area bitten  
  • Time bitten  
  • Identity of the spider, if possible.

The patient should be taken to the emergency room for treatment. The bite may not appear to be very severe and may take some time to progress to a more severe state. However, treatment is important to minimize complications. If possible, bring the spider to the emergency room for identification.

Poison Control, or a local emergency number
You will be instructed on what to do immediately following the bite. The patient should be taken to the emergency room. See poison control centers for the national telephone number.

Expectations (prognosis)
Fatalities from brown recluse spider bites are more common in children. With proper medical attention, survival past 48 hours usually indicates that recovery will follow. The ulceration may take up to six weeks to heal, with proper care.

Johns Hopkins patient information

Last revised: December 3, 2012
by Gevorg A. Poghosian, Ph.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.