Spiders to Worry About

In North America, two of the most dangerous spiders are the black widow and the brown recluse spider. These spiders, along with other potentially dangerous spiders, are the ones that cause people to worry. You can typically treat a spider bite at home by washing the infected area with soap and water, applying a cool compress to the wound and elevating the wound. In some instances, however, a spider's bite can lead to more severe reactions and you will need immediate medical attention.

Brown Recluse Spiders

• Brown recluse spiders are potentially dangerous spiders that hide during the day in ceiling cracks, attics, closets, piles of clothing and shoe boxes. They are mainly found in the southern and central parts of the United States. Brown recluse spiders are about 1/2 inch (1.3cm) in size and tan or dark brown in color. They have six eyes instead of the typical eight eyes that most spiders have. Brown recluse spiders are also known as fiddleback or violin spiders for the violin-shape marking on the top of their bodies. A brown recluse spider bite is typically painless; however, a person can suffer a severe localized reaction with a blister forming within the first 24 hours after a bite. A sunken, open sore may then form in 10 to 14 days. A brown recluse spider bite may take six to eight weeks to heal. You should see a physician if you are bitten by a brown recluse spider.

Black Widow Spiders

• Black widow spiders are timid spiders that prefer to create their crisscross webs in attics, sheds, garages and crawl spaces. One type of black widow, the northern widow spider, is often found in New England. The female northern widow spider is about 1/2 inch (1.3cm) in length and has a red hourglass shape on the underside of her black abdomen. Northern widow spider bites are immediately painful and produce pain that continues for 12 to 48 hours after the bite. People can suffer from headaches, dizziness, abdominal spasms and shortness of breath. Those especially at risk of death are children and unhealthy adults who may die within 12 to 32 hours from asphyxia, or lack of oxygen to the brain, if left untreated. You should seek immediate medical attention if bitten by a black widow spider.

Funnel-web Spiders

• Funnel-web spiders are another potentially dangerous type of spider. One type of funnel-web spider is the aggressive house spider, which often appears in basements of Pacific Northwestern homes. The aggressive house spider is an inch (2.5cm) or more in length and can bite a person with little provocation. The spider's bite may not be painful, but the venom can produce skin injuries or lesions that take more than a month to heal. A person may require surgery to repair lost tissue at the site of the bite. You can suffer from severe headaches, nausea, weakness or vision loss and should seek medical attention if bitten.

Common Sac Spiders

• A common sac spider is about 1/4 inch (.6cm) in size and whitish in color. The spider lives in tubular nests under bark or leaves in the Pacific Northwest. The common sac spider typically does not live around populated areas and is rarely found in homes. A common sac spider bite may be mistaken for a brown recluse spider bite because it produces pain, swelling and ulcerated sores around the area of the bite. You may suffer from muscular discomfort in the first hours after the bite. Contact a physician if your symptoms persist or worsen, but typically, the wound should improve within one to three days.