Spider Bites In
the Pacific Northwest
There is much
confusion regarding poisonous spiders found in the Pacific
Northwest (PNW). This confusion extends, in many cases, even to
the medical community. Only four spiders of medical importance
occur in the PNW. Two of these, sac spiders in the genus
Cheiracanthium, are rarely encountered. The other two, the
aggressive house spider, or hobo spider, and black
widow spider occur commonly in association with human
activity and present a real danger in terms of bites.
However, many
insect/spider bites reported in the PNW are, unfortunately,
attributed to a spider that does not even occur here, namely the
brown recluse spider. While the bite of the aggressive
house spider is similar (see below), the brown recluse spider
does not naturally occur in the PNW. The only known cases of
this spider have been linked to people moving into the PNW from
areas of known distribution.
The following
characteristics should help to separate these spiders. The
black widow spider (Latrodoctus sp.) occurs in the
PNW generally in dry, undisturbed areas such as firewood piles,
old lumber, dry crawl spaces, bales of hay, etc. The adult
female is 1-1/2 inch in diameter, including legs, jet black with
red markings on the underside of her abdomen. Males and
immatures may be striped white or yellow. This spider is
secretive, not aggressive, and rarely causes bite injuries. The
venom is neurotoxic and may lead to systemic effects, sometimes
even death.
Aggressive
house spider (Tegenaria agrestis) is common in the
PNW in and around houses, barns and sheds. It is a member of the
funnel-web spider group. This is a relatively large spider (body
size, excluding legs 3/8" - 5/8"; 1" - 1-3/4" including legs)
with long, hairy legs and chevron-shaped abdominal markings. The
venom is necrotic, causing open, localized wounds that may be
slow to heal. Males may be more venomous than females and become
quite common in mid-summer through the fall during the mating
season. Despite its aggressive nature, however, reported bites
from this spider are relatively rare. There are several closely
related species that look very similar but whose venom is not as
toxic.
Before beginning spider bite treatment, a person has to be sure
that he’s been bitten by a spider. Someone may develop such
symptoms as swelling, redness, itching, and pain after being
bitten by a spider, but other insects can cause the same
reaction. Even worse, the bite of the brown recluse spider can
cause a very nasty sore, but many don’t go to the doctor for at
least a few days after noticing the bite. This can make it
difficult to determine what actually bit the patient.
If a person is sure he’s been bitten by a spider, he may want
to perform some type of home care. However, there aren’t any
specific first aid spider bite treatments. He may apply an anti-itch cream, a cold
compress, or an
analgesic lotion to relieve the pain or itching. An oral
pain medication, such as acetaminophen or
ibuprofen, may be helpful as well.
Many people worry most about bites inflicted by black widow and
brown recluse spiders; a black widow spider may deliver a bite
that feels like a prick from a tiny needle. The unlucky
recipient of a bite from this spider may notice a bit of
swelling in the area and may also observe some light-looking red
marks. The obvious trouble begins after a few hours, when the
person begins to feel severe pain and notice stiffness. He may
also notice such symptoms as chills, fever, nausea, and pain in
the abdominal area; he should seek emergency spider bite
treatment from a local hospital or
urgent
care facility, which may include the use of ant venom. On
the way to the hospital, it may help to apply a tight bandage
above the bite to impair the spread of venom.
When the brown recluse spider bites, the bite area may sting a
bit. After a time, it may become reddened, and intense pain may
follow several hours later. Typically, a blister develops at the
bite site and fills with fluid, eventually developing into an
ulcer
that is large and deep. Though rare, these bites can lead to
death, particularly when children are bitten. If bitten by this
spider, it is best to tie a bandage above the bite area to slow
down the spread of the spider’s toxic venom, and then seek
medical help with spider bite treatment.
Pasted from <http://www.wisegeek.com/what-should-i-know-about-spider-bite-treatment.htm>
How to
Identify a Brown Recluse Bite
By
Rose Kivi
CDC/PHIL
Because so many spider bites look the same, it is difficult to
tell the difference between a brown recluse spider bite and
a bite from another spider. Usually, a person is not aware
that she is being bit by a spider. Of course, if you see a
brown recluse spider biting you, then you can be sure that
you have indeed been bitten by a brown recluse. Otherwise,
the best approach to identifying a brown recluse spider bite
is to keep an eye on the development of the bite.
Most brown recluse bites are not serious. A study conducted at
a southeastern U.S. university hospital found that the
majority of brown recluse bites did not cause serious
symptoms or long-lasting effects.
Instructions
Difficulty: Challenging
Step 1
Look at the bite. At the beginning, a brown recluse spider
bite appears as a small, white blister that is surrounded by
a red ring. There may be a white ring surrounding the red
ring. A few hours after the bite, the swollen red part of
the skin feels hard.
Step 2
Determine if the spider bite is causing more pain than a
normal spider bite would. Though not all brown recluse bites
cause pain, many do. Pain symptoms usually develop about 10
minutes after the bite. Symptoms of pain can range from a
slight to severe sting. If severe pain is present, see a
doctor, because you may be having a reaction to the brown
recluse spider's venom.
Step 3
Keep an eye on a bite that you suspect may be from a brown
recluse spider. In some people, the bite heals quickly, in
others, the bite continues to get worse. If it is a brown
recluse spider bite, the red area may continue to spread.
Spreading of the red area is not necessarily a cause for
concern, but it does warrant that you continue to keep an
eye on the bite to watch for further symptoms.
Step 4
Evaluate how you are feeling. People who have a reaction to
the venom of a brown recluse may feel dizzy, nauseous or
have muscle pain or the chills. These symptoms usually
appear one to two days after the bite. If you have any of
these symptoms, seek treatment from a doctor.
Step 5
Watch the bite for signs of infection and skin tissue death.
If the skin turns black, the skin appears to be wasting away
or if the blister turns into a large deep ulcer, go to a
doctor. Some brown recluse bites cause necrosis (tissue
death). Left untreated, necrosis is serious. In rare
instances, tissue death is severe and can result in the loss
of a large amount of skin and underlying tissues. Note: It
is normal for the blister to pop and a small ulcer to form
in its place. It is only if the ulcer is large, deep or
spreading that there is a cause for concern. Also, an ulcer
that will not heal is a cause for concern.
Tips & Warnings
Medical treatment for a brown recluse spider is antibiotics.
In cases of serious bites where the bite does not heal and
tissue death is spreading, surgery is performed.
Medical treatment for a brown recluse spider is antibiotics.
In cases of serious bites where the bite does not heal and
tissue death is spreading, surgery is performed.
Because spider bites and symptoms of spider bites can vary
greatly, this article should not be considered an all
inclusive list of possible outcomes. If you suspect that you
have been bitten by a brown recluse spider, call a doctor to
seek advice.
Because spider bites and symptoms of spider bites can vary
greatly, this article should not be considered an all
inclusive list of possible outcomes. If you suspect that you
have been bitten by a brown recluse spider, call a doctor to
seek advice.
Pasted from <http://www.trails.com/how_2149_identify-brown-recluse-bite.html>
