Symptoms of Hobo Spider Bite & It’s Treatment, Prognosis, Prevention

Hobo spider is a common term used to describe a spider found predominantly in the Pacific North-western United States, which includes the states of Washington, Idaho, Oregon and Utah. This type of spider is usually found along rail track (hence named hobo spider). It is also commonly found in other cracks and holes close to the ground such as beneath debris, building foundations, construction supplies, rock retained walls etc. Hobo spiders are usually not found indoors and generally not aggressive unless when they get trapped in skin or while chasing a prey. It is also known as the funnel weaver and aggressive house spider (though the second term is misleading).

A typical hobo spider has long legs (1 to 2 inches) and brown body (1/4 to ½ inches) with a gray abdomen with yellow markings. It is often difficult to spot a hobo spider because a large number of other spider species have similar physical characteristics. They belong to the funnel web spider family and can move very fast. They are not good at climbing but can move at a speed of 3 feet per second.

It has been noted that most of cases of hobo spider bite occurs between the months of July to September. This is probably because it is the mating season where the male spider searches for the female spider. The hobo spider bite is not painful and feels like a pinprick because of which it often goes unnoticed. Hobo spider bite, if left untreated, can lead to toxicosis which is often seen with necrotic arachnidism (i.e tissue death post spider bite). There may be nerve damage from tissue death leading to numbness and loss of sensation in limbs. Studies have shown that the symptoms of hobo spider bite are caused due to skin infection due to the action of methicillin resistant Staphylococcus aureus (MRSA). The stages of hobo spider bite are mentioned below:

• Initial painless stage
• Small indentation in 30 minutes
• Blister development in 15 to 35 hours
• Blister rupture followed by crater formation
• Necrosis and sloughing for 40 days
• Healing and permanent scaring within 45 days

Once a hobo spider bite is suspected, immediate first aid is advised. It is recommended to clean the bite area immediately with mild soap and water followed by cold compress over the bite to control pain and arrest swelling. It is also advised to elevate the affected leg or arm. Once the first aid has been administered, the affected individual is taken to a physician as soon as possible. In most of the cases, a tetanus booster is administered. If possible it is advised to bring the spider to the medical center for accurate diagnosis. Treatment modality for hobo spider bite includes management of the systemic effects caused by the bite. Based on the case, Corticosteroids or Anti-histamines are prescribed. In some cases of hobo spider bite, surgical repair of the area may be needed.

The prognosis and outlook of hobo spider bite is generally good. Recent studies have shown that the venom of hobo spider is not dangerous to humans. Most of the skin reactions that take place after the bite are short lived and limited in nature.

Hobo spiders like most spiders, attack humans only when they are trapped between the skin and other objects. They do not bite humans on purpose. A few measures can be taken to limit the chances of hobo spider bite. These measures are listed below:

• Limiting rubbish and other unwanted junk around the house, as these provide good places for spiders to breed.
• It is advised to learn about spiders that are present within the locality in terms of looks and hide out areas and be cautiously accordingly.
• It is advised to seal tools and any other open objects in plastic bags or closed boxes in sheds and garages to reduce the chances of spider hiding there.
• It is also recommendation to wear protective clothing such as long sleeved shirts, long pants, boots, gloves, hats, masks, eye wear while working with storied boxes and fire woods; and also while cleaning basements, attics, garages, sheds, crawl spaces etc.
• One should inspect and look inside shoes, gloves, boots, socks etc. before wearing them to ensure that that are no spiders hiding inside.
• It is important to check the fittings of window and doors regularly and seal any cracks or open spaces through which spiders may crawl in.
• Beds should be kept away from walls and only the bed leg should touch the floor. The bedding should not touch the floor and the area under the bed should be kept clean and empty.
• Regular vacuuming gets rid of spiders from homes.
• Sticky tapes should be used to catch spiders instead of chemicals.