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Brown Recluse Spider Bite


What should I know about a brown recluse spider bite?

Brown recluse spiders are venomous. The bite wound may heal on its own, but you will need treatment if the wound gets worse. The venom may cause severe skin and tissue damage after several hours or days.

What are the signs and symptoms of a brown recluse spider bite?

You may not feel anything at first. Within hours of the bite, you may feel mild burning or irritation in the bite wound. You may have any of the following:

  • Severe swelling and pain at the site
  • Blister that is blue in the center and ringed by redness
  • Pimple-like lesion with yellow or green pus
  • Ulceration (break in skin or mucous membrane)
  • Rash that itches
  • Dark urine
  • Fever, chills, nausea and vomiting, or seizures
  • Joint pain

How is a brown recluse spider bite diagnosed?

Your healthcare provider will ask about your symptoms and examine the injured area. He may ask about your medical history. You may need to have blood or urine tests or a skin biopsy. If you are able to capture the spider safely, bring it to your healthcare provider. This will help him plan the right treatment for you.

How is a brown recluse spider bite treated?

A brown recluse spider bite may heal on its own without treatment. It is important to clean the wound site with soap and water. If the bite wound gets worse or you get sick, you may need medicine or surgery.

  • Ice the wound: Ice helps decrease swelling and pain. Put ice in a plastic bag. Wrap the bag with a towel and put it on the site of the spider bite for 10 to 20 minutes.
  • Elevate the wound: Keep the bite area above the level of your heart to help decrease redness and swelling. If you were bitten on the arm or leg, prop it on pillows to keep the area elevated comfortably.
  • Compress the wound: A compression bandage around the wound can reduce pain and swelling.
  • Medicines:
    • Antibiotics: This medicine is given to help treat or prevent an infection caused by bacteria.
    • Antihistamines: This medicine may be given to help decrease itching.
    • Antivenom: There is no antivenom available for a brown recluse spider bite.
    • Steroids: This medicine may be given to decrease inflammation.
    • Td vaccine is a booster shot used to help prevent tetanus and diphtheria. The Td booster may be given to adolescents and adults every 10 years or for certain wounds and injuries.
  • Surgery: This is done if the damaged tissue around your wound needs to be removed.
  • Hyperbaric oxygen therapy: This is also called HBO. HBO is used to get more oxygen into your body. The oxygen is given under pressure to help it get into your tissues and blood. You may be put into a tube-like chamber called a hyperbaric or pressure chamber. You will be able to see your healthcare providers and talk with them through a speaker. You may need to have this therapy more than once.

How can a I prevent a brown recluse spider bite?

  • Recognize the spider: Brown recluse spiders are usually brown and have a pattern on the back that looks like a violin.
  • Learn where to find them: These spiders live in the central and southern parts of the United States. They can be found from April to October and are active at night. They prefer to live in dark, warm, dry places. Some examples are under rocks, boards, and woodpiles, in dark corners, and under furniture.
  • Use caution: These spiders are not aggressive. They bite people only when threatened. Make noise when you enter attics or other spaces where spiders may live. Noise may scare them away. Use caution when you remove a web or spider.
  • Be proactive: Clean closets, sheds, and attics completely. Shake out clothes or shoes that are lying on the floor or stored before you put them on. Check your sheets before you get into bed. Remove woodpiles and other trash from outside areas, especially piles where spiders can live. Wear gloves, long sleeved shirts, pants, and shoes when you work near wood or garbage piles.

What are the risks of a brown recluse spider bite?

  • Treatment for a brown recluse spider bite may have side effects. Medicines may cause nausea or vomiting. You may have sore throat, or your skin may become pale or yellowish. You may develop soreness, redness, or swelling in the muscle where the tetanus shot was given. Even with treatment, your wound may become worse, or you may get very sick from having the poison in your body.
  • Untreated spider bites may lead to more serious problems, such as swelling and infections. Severe swelling may cause blood supply problems in the area. Infection may spread to other parts of your body and become life-threatening. People who have diabetes, blood supply problems, or have decreased ability to fight infection are at a higher risk of problems.

When should I contact my healthcare provider?

  • You have a rash, itching, or swelling after you take your medicine.
  • The bite becomes red and swollen.
  • You have pain or problems moving the injured part or get tender lumps in the groin or armpits.
  • Your wound continues to get larger.
  • You have questions or concerns about your condition or care.

When should I seek immediate care or call 911?

  • You have a fever or chills.
  • The skin around your wound gets red, or the wound gets more painful.
  • You have a headache, or nausea and vomiting.
  • You have numbness or tingling in the bite area.
  • You have trouble talking, walking, or breathing.
  • Your urine is darker, or you urinate less than is usual for you.
  • Your wound does not stop bleeding even after you apply pressure.
  • Your wound or bandage has pus or a bad smell.

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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