Spider Bites (Black Widow and Brown Recluse)

Pictures Black Widow Spider and Brown Recluse Spider

Most spiders in the U.S. are harmless. However, black widow and brown recluse spider bites are dangerous, and sometimes life-threatening. Black widow and brown recluse spider bites need immediate medical treatment.

The black widow and brown recluse spiders are more common in the southern states of the U.S. They prefer warm, dry climates and undisturbed areas such as basements, closets, woodpiles, attics, or under sinks. The black widow spider is a small, black, shiny spider with a red hourglass marking on its belly. The brown recluse spider is sometimes termed a "violin spider." It is about an inch long and has a marking resembling a violin on the upper part of its back. Bites from both the black widow and brown recluse spiders are dangerous to humans and require prompt emergency medical care.

If you think that, you or someone you know has been bitten by a black widow or brown recluse spider, call 911 or go to the nearest Urgent Care or Emergency Department for treatment.

Bites from most (non-poisonous) spiders cause local redness, irritation, and pain that usually can be treated at home using an over-the-counter pain reliever along with the application of cooling packs or a wet cloth to relieve swelling. These local reactions usually resolve without treatment over 7-10 days.

Rarely, an individual can have an allergic reaction to a spider bite, even to a bite from a non-poisonous spider, but allergic reactions are more likely to be due to contact with a spider than from a spider bite.

The most common localized symptoms of a black widow spider bite include immediate pain, burning, swelling, and redness around the bite.

A black widow spider bite is said to feel like a pinprick, although victims may not realize that they have been bitten. Sometimes double fang marks may be seen at the location of the bite.

The most common localized symptoms of a black widow spider bite include:

• immediate pain,
• burning,
• swelling, and
• redness around the bite.

The bite of a brown recluse spider leads to a mild stinging, followed by local redness and severe pain that usually develops within eight hours but may occur later. Some reports of brown recluse bites describe a blue or purple area around the bite, surrounded by a whitish ring and a large red outer ring in a "bull's eye" pattern. A fluid-filled blister forms at the site and then sloughs off to reveal a deep ulcer that may turn black.

• Fever
• Nausea
• Vomiting
• Headache
• Abdominal pain
• Joint pain or stiffness
• Feelings of malaise
• Rash
• Muscle tension or cramping

If a spider was not observed inflicting the bite, it is difficult if not impossible to determine whether a spider bite occurred, since many conditions of the skin may produce the same symptoms as a spider bite. Streptococcal and Staphylococcal infections, early lesions of herpes simplex or zoster, burns, stings, or bites from other arthropods or insects (including fleas, bedbugs, mosquitos, biting flies, ants, and ticks), thorn injury, and early Lyme disease all may be characterized by skin findings similar to those from a spider bite.

Spiders rarely bite people, and only if threatened. People often think they have spider bites when the irritation is from another cause.

Treatment for spider bites should include:

• Wash the site of the spider bite well with soap and water.
• Apply a cool compress or ice pack over the spider bite location.
• Over-the-counter pain relievers may be used to relieve symptoms. (Remember, not to give aspirin to children; use acetaminophen or ibuprofen instead).

Call the doctor or seek emergency treatment if the victim is a young child, if you think the bite may have been from a black widow or brown recluse spider, if any signs of an allergic reaction occur, if the bite area becomes infected, or if the victim develops a rash or severe illness.

If possible, retrieve the spider and bring it with you to the healthcare practitioner so that it can be definitively identified.

A tetanus booster shot may be necessary, depending on the date of the patient's last immunization.

Treatment for a bite from a black widow or brown recluse spider may include:

• Wash the bite area with soap and water.
• Elevate the area to prevent the spread of the venom.
• Tie a snug bandage above the area (if on an arm or leg) to further reduce the spread of the venom, but do not make the bandage too tight that it impairs blood circulation.
• Always seek immediate emergency medical care. An anti-venom medication is sometimes given for black widow spider bites. Doctors use different types of medications to treat spider bites, including pain relievers, muscle relaxants, and/or corticosteroids. Sometimes hospitalization is required after a black widow or brown recluse spider bites.
• If possible, retrieve the spider and bring it with you to the health care practitioner so that it can be definitively identified.
• A tetanus booster shot may be necessary, depending on the date of the patient's last immunization.

Calling the Poison Control Center (24-hour hotline at 1-800-222-1222 in the U.S.) allows you to reach toxicology experts who can work with a healthcare provider in establishing the proper diagnosis and management of a spider bite.

Most spiders do not have mouthparts strong enough to penetrate human skin, and the majority of spiders that are found in the U.S. are actually harmless. There are two notable exceptions, the black widow spider and the brown recluse spider, which are both dangerous to humans.

Spider bites are fortunately uncommon. In many cases, presumed the bites are actually due to another skin condition or an insect sting.

Rarely, black widow spider bites are fatal; however, a few individuals have died from brown recluse spider bites, which are more common in children than in adults.