Mayo Clinic Health Manager
Get free personalized health guidance for you and your family.
Get Started
About our e-newsletters
- Free e-newsletters
- Mayo Clinic expertise
- We do not share your e-mail address
Housecall, our weekly general-interest e-newsletter, keeps you up to date on a wide variety of health topics with timely, reliable, practical information, recipes, blogs, questions and answers with Mayo Clinic experts and more. Our biweekly topic-specific e-newsletters also include blogs, questions and answers with Mayo Clinic experts, and other useful information that will help you manage your health.
Housecall Archives
Mayo Clinic Housecall
Stay up to date on the latest health information.
What you get
- Free weekly e-newsletter
- Mayo Clinic expertise
- Recipes, tools and other helpful information
- We do not share your e-mail address
Only a few spiders are dangerous to humans. Two that are present in the contiguous United States and more common in the Southern states are the black widow spider and the brown recluse spider. Both prefer warm climates and dark, dry places where flies are plentiful. They often live in dry, littered, undisturbed areas, such as closets, woodpiles and under sinks.
Black widow spider
The female black widow gives the more serious bite, but its bite is rarely lethal. You can identify this spider by the red hourglass marking on its belly. The bite feels like a pinprick. You may not even know you've been bitten. At first you may notice only slight swelling and faint red marks. Within a few hours, though, intense pain and stiffness begin. Other signs and symptoms of a black widow spider bite include:
- Chills
- Fever
- Nausea
- Severe abdominal pain
Brown recluse spider
You can identify this spider by the violin-shaped marking on its top. The bite produces a mild stinging, followed by local redness and intense pain within eight hours. A fluid-filled blister forms at the site and then sloughs off to leave a deep, enlarging ulcer. Reactions from a brown recluse spider bite vary from a mild fever and rash to nausea and listlessness. On rare occasions death results, more often in children.
If bitten by a spider
Clean the site of the spider bite well with soap and water. Apply a cool compress over the spider bite location. Aspirin or acetaminophen (Tylenol, others) may be used to relieve minor signs and symptoms in adults. Don't give aspirin to children. Give children acetaminophen instead. Treatment in a medical facility may be necessary for children under 6 years old and for adults with severe signs and symptoms.
If bitten by a brown recluse or black widow spider
- If possible, make a positive identification. If the spider bite is on an arm or a leg, tie a snug bandage above the bite to help slow or halt the venom's spread. Ensure that the bandage is not so tight as to cut off circulation in the arm or the leg.
- Use a cold cloth at the spider bite location. Apply a cloth dampened with cold water or filled with ice.
- Seek immediate medical attention. Treatment for the bite of a black widow may require an antivenom medication. Doctors may treat a brown recluse spider bite with corticosteroids.
