How to Treat a Spider Bite

A spider bite can lead to itching and pain. While some spider bites are quite dangerous, the majority can be treated easily. Recognizing the bite is helpful, but it is still important to seek medical care, as misidentification can occur. Even if a healthcare professional confirms that the bite is not dangerous, it is recommended to monitor the bite at home and watch for any signs of adverse reactions.

Examine the body of the Sydney funnel-web spider. This aggressive spider has a shiny, dark body similar to a tarantula and is commonly found in the dark, damp areas of southeastern Australia. Immediate medical care is necessary if bitten by a Sydney funnel-web spider, as the symptoms of poisoning can progress rapidly.

• The initial bite will be extremely painful. Although it may not cause significant swelling or blisters, the victim will sweat, experience facial spasms, and may feel tingling around the mouth. In this case, it is crucial to go to the hospital for treatment with anti-venom as soon as possible.

Recognizing the large, furry body of the Brazilian wandering spider. The Brazilian wandering spider is a nocturnal species known for its large size and aggressive nature. Found primarily in the southern United States, these spiders have a hairy brown body about 5 cm long, with a black streak running across their abdomen. Unlike other spiders, they do not build webs; instead, they roam the night and often seek shelter in banana plants or dark corners.

• The bite of this spider causes swelling and localized pain, which may radiate upwards along the body. Symptoms can include nausea, vomiting, high blood pressure, difficulty breathing, and in some cases, erectile dysfunction in men. Antivenom is available to alleviate symptoms, and fatalities are rare.

Be aware of the blistering bite from the brown recluse spider. Brown recluse spiders come in various shades of brown but always have a distinctive violin-shaped marking on their back and long, slender legs. The bite initially feels sharp, followed by intense pain over the next eight hours. The blister will eventually burst, leading to a spreading ulcer, and the area around the bite will show blue or red streaks, indicating tissue damage.

• Other symptoms may include fever, rash, and nausea.
• While the bite can look alarming, no fatalities have been recorded in the U.S. Antivenom for this spider's bite is not available, but treatments like surgery and antibiotics are used to treat the wounds.

Look for the hourglass-shaped red spot on the black widow spider. The black widow is a large, shiny black spider with a distinctive red hourglass marking on its abdomen. Found throughout North America, its bite initially causes a sharp sting, followed by redness and swelling. Within 30 minutes to several hours, the pain becomes severe and accompanied by muscle stiffness.

• Other potential symptoms include intense abdominal pain, nausea, fever, and chills. While typically not fatal to healthy adults, the bite of the black widow can result in permanent limb loss if untreated. Antivenom is available to treat the venom.
• Note that the black widow and brown recluse are the only dangerous venomous spiders in the U.S. Both species prefer warm climates and dark, dry places like closets or piles of wood.

Take caution with the red stripe on the redback spider's back. Closely related to the black widow, the redback spider is found throughout Australia, especially in urban areas. Only the female spider is dangerous. These spiders have a pea-sized black (sometimes brown) body with a distinctive red stripe on their back and a red hourglass-shaped marking on their abdomen.

• A person bitten by a redback spider may experience sweating, nausea, muscle weakness, and intense pain, which can sometimes be severe.
• Thanks to antivenom treatment, there have been no recorded fatalities from redback spider bites.

Seek immediate medical attention. See a healthcare professional right away, even if you believe the bite isn't serious. It's often difficult to accurately identify a spider bite.

• It is also advisable to administer an antihistamine injection as soon as possible, even if you’re unsure which type of spider bit you. While antivenoms are typically available on ambulances, it still takes time to select and administer the correct medication.

Apply an ice pack. This step will help slow the spread of venom and reduce swelling.

• If you suspect you've been bitten by a Brazilian wandering spider, apply a warm compress. This will help lower blood pressure at the bite site.

Slow the spread of venom. If the bite is on your arm or leg, elevate the limb and wrap a bandage above the bite site. Limit movement to slow the progression of the venom.

• Be careful when bandaging to avoid restricting blood flow.
• Do not apply a tight bandage to the bite area if you suspect a redback spider bite. Since the venom from this spider spreads slowly, this approach will not be helpful and may cause more pain.

Bring the spider to the healthcare facility if possible. Even if the spider has been crushed, try to collect it and take it to the hospital. A blood test can help identify which spider species caused the bite, but having the actual specimen will speed up the identification process.

• You can preserve the spider in rubbing alcohol.

Clean the bite with cool soapy water. Even if you believe the bite isn’t serious, it’s a good idea to visit a healthcare professional for an evaluation. If they confirm the bite is harmless, you can begin treatment by washing the wound with soapy water to help prevent infection.

Apply something cold, such as an ice pack. This will help alleviate pain and reduce swelling for 20 to 30 minutes.

Elevate the bitten limb. This will help reduce swelling and inflammation.

Ease mild pain with aspirin or acetaminophen (Tylenol). Children and teenagers who have recently recovered from chickenpox or have flu-like symptoms should not take aspirin.

Monitor for the next 24 hours to ensure symptoms don't worsen. In the next few days, the pain and swelling from the bite should subside. If symptoms don’t improve, contact a poison control center or see a doctor.

• If the bite is about the size of a coin, you can monitor it at home. However, if the bite expands with red streaks and swelling around the wound, seek medical attention immediately.

Know when to see a doctor. In certain cases, bites from non-venomous spiders can lead to allergic reactions. Call emergency services immediately if the person bitten by the spider shows any of these symptoms:

• Difficulty breathing
• Nausea
• Muscle spasms
• Streaks radiating around the bite
• Throat tightening, making swallowing difficult
• Profuse sweating
• Dizzy or lightheaded feelings

• If an unwanted spider attaches to your skin, gently flick it away—if you crush the spider, its fangs may remain lodged in your skin.
• Regularly clean your home—most spiders prefer dark, quiet places.
• Shake out clothes and shoes left on the floor or in the closet before wearing or putting them on.
• Wear gloves and tuck pant legs into socks when working in basements, outdoors, or in areas where spiders tend to live.
• Move your bed away from corners and walls to prevent spiders from hiding in your bed linens.
• Properly seal your home to minimize the risk of spider infestations.
• Insect repellents containing DEET can help keep spiders away.
• Inform an adult immediately if there is concern about a venomous spider.
• Never poke at a spider bite. It may rupture and become infected.