Hobo Spider Bite: Symptoms and Treatment

There are three types of hobo spiders: Tegenaria agrestis, T. gigantic, and T. domestica.

Hobo spiders are also known as “aggressive house spiders” and they do bite! Hobo spiders are typically found outside homes in rock piles or beneath logs or lumber. They find garages, barns and other exterior buildings the perfect hiding places.

Inside your homes, be careful when rummaging through your closet or walking in dark basements. Hobo spiders can breed even in the crawl spaces, attics, duct work and registers. Your shoe boxes and racks can be a good place for hobo spiders to live in, as well as old clothing, storage boxes and under furniture.

Hobo spiders are considered hunting spiders and have external features that may be similar to common harmless spiders. They are distinguished through the distinct yellow chevron (^) shaped markings on their abdomens.

Hobo Spider Venom

How poisonous is a hobo spider bite? Hobo spiders do not generally bite unless provoked. From its common name aggressive house spider, the hobo spider that tends an egg sac becomes more aggressive because it sees its egg sac as being threatened.

In a US laboratory study on rabbits induced with hobo spider bites, the bites left lesions on the rabbits and therefore were considered very dangerous. Hobo spider bites may cause necrosis (death of body tissue) in human beings.

Hobo Spider Bite Identification

How do you distinguish a hobo spider bite from other insect bites? The hobo spider bite can also feel warm for a few hours and the first 24 hours of the bite is similar to the effects of a mosquito bite. To distinguish it from other insect bites, be aware of some changes in the area bitten by a hobo spider.

• The blister caused by the bite breaks open within one to two days after the bite has taken place and forms an oozing open ulceration.
• Most hobo spider bites are minor. However, some can cause an erupting lesion or a flesh hole, which is a result of dead tissue.
• The size of the lesion ranges from a pea size to that of a half dollar size and sometimes bigger.
• Underlying tissues of the bite can be seen after the dead tissue gradually peels.
• The sunken wound caused by the hobo bite may take weeks and even months to recover. An ugly scar is a reminder that the bite is healed.

Hobo Spider Bite Symptoms

A hobo spider bite is initially painless, but it can be serious. Dry hobo spider bites, which constitute about 50 percent of all hobo spider bites, do not cause a serious threat to the victim since the biting spider does not release venom. However, in general hobo spider is poisonous.  When hobo spider poisoning (also known as “tegenarism”) is severe, it will take time to heal and may leave scarring.

When a hobo spider injects venom (envenomation) on a victim, the following symptoms may be observed:

• Immediate redness around the bitten body portion but the redness disappears after a few hours.
• Headache
• Nausea
• Fatigue
• Temporary memory loss
• Weakness
• Vision problems

First Aid for a Hobo Spider Bite

A hobo spider bite can be painless but very serious. If you have been bitten by a hobo spider, stay calm (very important) and apply first aid.

• Don’t panic: Panicking or moving around too much after you’ve been bitten by a hobo spider could spread the spider venom from the bite area to other areas of your body faster. Remain calm.
• Wash the affected area and bandage it: A clean bandage can be placed on the bite wound after washing the spider bite area using either soap, alcohol or any other astringent.
• Take a pain reliever: A pain reliever such as benzocaine can be applied to the wound when pain is severe.
• Apply cold compress: You can also apply ice to the hobo spider bite area to delay absorption of the venom.

If you can, catch the spider (dead or alive, just don’t get bitten again) that bit you — for proper identification. If it’s a hobo spider (or another poisonous spider) that bit you, your doctor or a health provider can give you the appropriate treatment.

Hobo Spider Bite Treatment

Treatment for hobo bites is the same as that for brown recluse spider as they have almost the same nature of envenomation.

• Remove the venom: Surgical removal of the venom by a physician or a health care provider should be immediately done after the bite has been identified as hobo spider bite. You must not attempt to remove the venom yourself.
• Apply or take corticosteroids: This can be done within 24 hours of being bitten. Corticosteroids can be oral, topical or injectables; they relieve inflammation of the wound.
• Inject with phentolamine: For severe cases, a phentolamine injection may be advised to relieve pain.
• Take antibiotics: To prevent bacterial infection of the affected area, your doctor can prescribe antibiotics and antihistamines. This is given in order to speed up or avoid complication during the healing process.

Recovering from a hobo spider bite could take as short as two weeks or as long as two years, depending on the person’s age, physical and psychological disposition to healing.