Hobo Spider Bites

The hobo spider is sometimes known as the aggressive house spider. This species was introduced to the United States from Europe and has been implicated in human bite cases in the Pacific Northwest and many other states throughout their area of distribution.

Signs and Symptoms

Bite symptoms include a slight prickling sensation and a small, numb, hard area that appears within 30 minutes after the bite. These symptoms may also include a reddened area of up to 3 or more inches in diameter. This reddened area will become blistered between 15 to 35 hours after the bite, and about a day later the blister breaks and oozes. A necrotic lesion may form and can range from 1/2 to 1 inch or more in diameter and take several months to heal. Painful headaches also have been associated with hobo spider bites.

Hobo spider bite symptoms vary from person to person. No symptoms develop in about 50 percent of people bitten by a hobo spider. Therefore, it is very important to collect any spider that bites and, if possible, submit the specimen to a medical expert who can provide an accurate identification.