What is a brown recluse spider?

Brown recluse spiders are also called violin or fiddleback spiders because of the dark violin- or fiddle-shaped mark on their back. They are about 0.5 in. (1.3 cm) long and have six eyes grouped in three pairs rather than eight eyes like other spiders. They are found most often in the Southern, Western, and Midwestern areas of the United States. They live in hot, dry, dark areas, such as wood or rock piles, attics, basements, cupboards, drawers, and boxes.

A brown recluse spider bite can become infected, and the infection can spread through the body, so it is important to get medical help right away.

What are the symptoms of a brown recluse spider bite?

Brown recluse spider bites don't always hurt right away. In fact, you may not know that you have been bitten until other symptoms appear. Symptoms of a brown recluse spider bite include:

• Reddened skin that may be followed by a blister that forms at the bite site.
• Mild pain or itching that may get worse several hours after the bite.
• An open sore (ulcer) or black skin can appear around the bite. This can happen a week or more after you were bitten. This may take months to heal.

Some people have a more severe reaction to brown recluse spider bites. These symptoms include:

• Fever and chills.
• Skin rash all over the body with many tiny, flat purple and red spots.
• Nausea and vomiting.
• Joint pain.

What should you do if you think you've been bitten by a brown recluse spider?

• Remain calm. Try to stay relaxed.
• Wash the bite area with soap and water.
• Apply a cool, wet cloth or ice pack to the bite area to reduce swelling.
• Elevate the bite area if it is on a limb, such as your arm or leg.
• Try to positively identify the spider or try to take a picture of it. If you are able to safely capture and transport the spider, bring it with you to show your doctor.

Contact your doctor if an open sore and black, dead skin develop. A brown recluse bite can become infected, and the infection can spread through the body, so it is important to get medical help right away.

How is it diagnosed?

A brown recluse spider bite is diagnosed through a physical examination and questions about the bite. You should be prepared to describe the spider, where and when the bite took place, and what you were doing at the time. (If you are able to safely capture and transport the spider, bring it with you to show your doctor.) Your doctor will ask what your main symptoms are, when they began, and how they have developed, progressed, or changed since the bite.

How is a brown recluse spider bite treated?

Treatment depends on how severe the bite is. For bites that:

• Do not develop open sores, treatment includes applying a cold compress, elevating the bite area, and avoiding moving the bite area.
• Cause an open sore (ulcer), treatment includes washing the area daily with soap and water. Treatment also includes covering the wound to reduce the risk of infection.

Medicines that may be used include:

• Pain medicine, such as acetaminophen (Tylenol) or nonsteroidal anti-inflammatory drugs (NSAIDs). NSAIDs include naproxen (Aleve) and ibuprofen (Advil, Motrin). Be safe with medicines. Read and follow all instructions on the label. Do not give aspirin to children and teens. It has been linked to Reye syndrome, a rare but serious illness.
• Antihistamines to help relieve itching.
• Antibiotics, if an infection is present.
• A tetanus vaccine if the person is not up to date on vaccinations.

Medicine to counteract brown recluse spider venom (antivenom) is not available.