Brown recluse, or fiddle (Loxosceles),
spiders are about
0.5 in. (1.3 cm) long with a
dark violin-shaped mark on the combined head and midsection (cephalothorax).
They are found most often in the south-central part of the United States and
some parts of southern Canada and live in hot, dry, abandoned areas, such as
wood or rock piles.
Brown recluse spider bites don't always hurt right away. In fact,
you may not know that you have been bitten until other symptoms appear.
Symptoms of a brown recluse spider bite include:
Reddened skin followed by a blister that forms
at the bite site.
Mild to intense pain and itching for 2 to 8 hours
following the bite.
An open sore with a breakdown of tissue
(necrosis) that develops within a few hours to 3 to 4 days following the bite.
This may take months to heal.
Some people have a severe, systemic (whole-body) reaction to brown
recluse spider bites, including the rapid destruction of red blood cells and
anemia (hemolytic anemia). Symptoms include:
Fever and chills.
Skin rash all
over the body with many tiny, flat purple and red spots.
Nausea or
vomiting.
Joint pain.
What should I do if a brown recluse spider bites me?
If you think you have been bitten by a brown recluse spider:
Remain calm. Too much excitement or movement
will increase the flow of venom into the blood.
Apply a cool, wet
cloth to the bite or cover the bite with a cloth and apply an ice bag to the
bite.
Do not apply a tourniquet. It may cause more harm than
benefit.
Try to positively identify the spider or catch it to
confirm its type.
A brown recluse bite can be serious and may require immediate
medical care. Call your doctor if:
You have severe symptoms throughout your
body.
An open sore and black, dead tissue (necrosis)
develops.
How is a brown recluse spider bite diagnosed?
A brown recluse spider bite is diagnosed through a physical
examination and questions about the bite. You should be prepared to describe
the spider, where and when the bite took place, and what you were doing at the
time. Your doctor will ask what your main symptoms are, when they began, and
how they have developed, progressed, or changed since the bite.
How is it treated?
Medicine to counteract brown recluse spider venom is not available
in the United States or Canada. Treatment depends on how severe the bite
is.
For bites that do not develop open sores,
treatment includes applying a cold compress, elevating the bite area, and
avoiding moving the bite area.
If you develop an open sore and dead
skin (necrosis), treatment includes removing the dead skin from the sore. This
may involve follow-up and replacing the dead skin with new skin (skin
grafts).
Medicine that may be used include:
Pain medicine, such as acetaminophen (Tylenol)
or
nonsteroidal anti-inflammatory drugs (NSAIDs). NSAIDs
include naproxen (Aleve) and ibuprofen (Advil, Motrin). Do not
give aspirin to anyone younger than 20 because of the risk of
Reye's syndrome.
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information. For more information, click here.
