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Black Widow Spider Bite

Medically reviewed by Last updated on Oct 3, 2022.

What do I need to know about a black widow spider bite?

The venom from a black widow spider is poisonous. Symptoms of a reaction to the venom start about 30 minutes after the bite. Symptoms are usually mild and stop within a few days, but severe symptoms that last several days are possible. Venom can spread from the bite to other parts of your body. It can damage your muscles, nerves, or organs.

What are the signs and symptoms of a black widow spider bite?

  • A sharp pain like a pinprick, or pain that spreads from the bite area to other areas
  • Red, numb, tingling, stinging, or burning skin at the bite area
  • Muscle cramps or spasms
  • Nausea or vomiting
  • A cold sweat

How is a black widow spider bite treated?

Treatment depends on how severe your symptoms are. You may need any of the following:

  • NSAIDs , such as ibuprofen, help decrease swelling, pain, and fever. This medicine is available with or without a doctor's order. NSAIDs can cause stomach bleeding or kidney problems in certain people. If you take blood thinner medicine, always ask if NSAIDs are safe for you. Always read the medicine label and follow directions. Do not give these medicines to children younger than 6 months without direction from a healthcare provider.
  • Prescription pain medicine may be given. Ask your healthcare provider how to take this medicine safely.
  • Muscle relaxers may be given to relieve cramps or spasms.
  • A tetanus vaccine is a booster shot used to help prevent tetanus. Tetanus is a severe infection that can develop in the bite wound.
  • IV fluids may be needed to prevent dehydration and kidney failure.
  • Antivenom may be given if your symptoms are severe or you are at increased risk. Antivenom can help slow or stop your symptoms.

How do I manage my symptoms?

  • Elevate your wound above the level of your heart as often as you can. This will help decrease swelling and pain. Prop a bitten arm or leg on pillows or blankets to keep it elevated comfortably.
  • Apply ice to your wound for 15 to 20 minutes every hour or as directed. Use an ice pack, or put crushed ice in a plastic bag. Cover it with a towel before you apply it to your wound. Ice helps prevent tissue damage and decreases swelling and pain.
  • Care for your wound as directed. Carefully wash the wound with soap and water. Dry the area and watch for signs of infection, such as fever, redness, and swelling.

When should I contact my healthcare provider?

  • You have increased pain or a change in how your pain feels.
  • You have a fever or a headache.
  • Your wound is red, swollen, or draining fluid.
  • Your eyes become sensitive to light.
  • You have pain when you move the bitten body part, or the part is difficult to move.
  • You get tender lumps in your groin or armpits.
  • Your symptoms spread from the bite to other parts of your body.
  • You have questions or concerns about your condition or care.

When should I seek immediate care or call 911?

  • You have severe abdominal pain.
  • Your wound turns blue or black and smells foul.
  • Your muscles become stiff and start to cramp or spasm.
  • You have tremors or trouble breathing, talking, or walking.
  • Your heart is racing.
  • You have chest pain, tightness, or heaviness that may spread to your shoulders, arms, jaw, neck, or back.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your healthcare providers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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