Black Widow Spider Bites

Latrodectus hesperus

Overview | Prevention | Video | Health and Medical Disclaimer

Black Widow Spider Bites

The female black widow spider, though it is the most venomous spider in North America, seldom causes death as it injects a very small amount of poison when it bites. Reports indicate human mortality at well less than 1% from black widow spider bites.

Symptoms of a Black Widow Spider Bite

If you are bitten by a black widow spider you may experience one or more of the symptoms listed below. Poison injected by the spider at the time of the bite causes the symptoms, not the bite itself.

Small children and the elderly are often more symptomatic and can have a more severe reaction to the venom of the black widow spider.

If you are not sure if you were bitten by a black widow spider, you should know that the following symptoms can be caused by or resemble other medical conditions. Always consult a physician for a diagnosis.

Symptoms may vary for each individual.

• Local pain, redness, burning and swelling at bite site (Some may have minimal pain from the bite itself)
• Abdominal pain (pain can be similar to appendicitis) and localized or generalized muscle cramps (stomach, shoulders and back)
• Headache
• Rash and itching
• Sweating
• Eyelid swelling
• Salivation, tearing of the eyes
• Weakness, tremors or paralysis (especially in the legs)
• Nausea and/or vomiting
• Dizziness and/or fainting
• Chest pain (similar to a heart attack)
• Respiratory difficulties may follow
• High blood pressure
  

Treatment:

Depending on your reaction to the bite you may have mild or severe symptoms. If you, or the person bitten, is experiencing more than mild pain or symptoms throughout your body seek treatment at the emergency department of a hospital. If symptoms are severe, or the person has trouble breathing, convulsions or cannot wake up, call 911 for immediate medical assistance and transportation to hospital. Early treatment is important, especially for young children and elderly people. A physician can evaluate the severity of the bite and give specific antivenin or treatment to relieve pain or respiratory problems if necessary. Persons with heart conditions or other health problems may require a hospital stay if bitten by a black widow spider.

First aid measures:

• Wash the bite site with soap and water
• Apply an ice pack wrapped in a cloth over the bite location
• To help prevent an infection apply an antibiotic lotion or cream to the bite site
• Elevate if the bite is on a limb (arm or leg) to prevent swelling
• Seek immediate emergency care
• Try to collect the spider specimen in a small jar or plastic bag for examination by a spider expert, even if you have crushed it.
• Treatment in a medical facility may be necessary.

Common Questions:

How to identify a black widow spider?
How can I keep black widow spiders out of my house and yard?
Do female black widows kill and eat the male after they mate?

Black Widow is considered the most venomous spider in North America.

The venom of the black widow spider is 15 times as toxic as the venom of the prairie rattlesnake.

Only the female Black Widow is dangerous to humans; males and juveniles are harmless.

The female Black Widow will, on occasion, kill and eat the male after they mate

More than 35,000 spider species of spiders occur in the World.

About 3,400 species in 64 families are found in North America.

Black Widow Spider: Overview | Prevention
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