Residents in this area enjoy an environment free from many types of poisonous spiders. But picking a sweater up off the floor to see a spider nestled underneath, or flipping on the bathroom lights in the morning as one scuttles across the shower can make your heart feel like it’s skipped a beat.
In this part of Oregon, dangerous spiders are rare. The Oregon Department of Agriculture reports that of the 500 species of spiders in Oregon, the black widow spider, hobo spider, giant house spider and yellow sac spider are the four that garner the most interest.
“Because of their delicate mouth parts, there are very few spiders that can physically bite humans,” said Anne Marie Collum, DO, a resident at Samaritan Internal Medicine – Corvallis. “A bite from a black widow is potentially the most dangerous spider in the area. The venom affects the nervous system and can lead to muscle cramps and nausea.”
According to Dr. Collum, if you have reason to believe you were bitten by a black widow, you should get medical attention immediately. Even if you aren’t experiencing a severe reaction you may need a tetanus shot and the doctor will want to monitor you in case you do develop other symptoms.
A bite from a hobo, giant house or yellow sac spider may result in pain, swelling or fever but unless you have other risk factors, Dr. Collum reports that severe tissue damage or other serious problems are extremely unlikely.
“With spider bites, the most common complaints are redness, pain, swelling and itching which may last about a week,” said Dr. Collum. Occasionally, people may experience headache or nausea, although these symptoms usually improve within 24 hours.
If you suspect you have a spider bite, Dr. Collum recommends the following steps:
- Wash the bite with soap and water
- Apply an antibiotic ointment
- Elevate the affected area and apply an ice pack for 10 minutes to help with swelling
- Use topical cortisone cream or an oral antihistamine if itching and swelling become bothersome
The Oregon Department of Agriculture reports that hobo spiders and giant house spiders are seen most often in the late summer and early fall, usually at night, as the males emerge to find a mate. Black widow spiders live primarily in their web in a dark garage or crawl space, and yellow sac spiders live in white sacs in the corner of windowsills or under objects such as planters.
To help prevent spider bites, reduce the number of spiders in your home. Remove visible webs and spiders in and around the home regularly, and keep bedding and clothing off the floor. Make sure your home is sealed around windows and doors. Spider traps may also be effective if used correctly.
If you’re unsure a spider bite needs medical attention, call your medical provider or schedule an appointment at one of our walk-in clinics.
Anne Marie Collum, DO, is a resident at Samaritan Internal Medicine – Corvallis as a part of Samaritan’s Graduate Medical Education Program. She provides primary care to patients of all ages and can be reached at 541-768-5140.