Spider bite

Spiders are arthropods, not to be confused with insects. There are over 40,000 species worldwide.

 

They usually do not bite unless they feel threatened, and bites often go completely unnoticed.

 

When they do cause symptoms, there is usually redness, pain and swelling of the skin in the area of the bite. The symptoms are so common, and coincide with so many types of bites, that it is difficult to be sure that the bite was a spider bite if they are not seen at the time of the bite. Some species deliver a venom strong enough to cause severe symptoms; this is the case with black widow spider bites, which can cause severe chest and abdominal pain, nausea, vomiting, tremors, sweating, and a drop in blood pressure. Recluse spider bites can also be severe, with severe pain, fever, hypotension, and a skin lesion that turns purple and eventually develops into an ulcer.

 

It is usually diagnosed when the spider that caused the bite is seen. Photographing or describing the spider may help the physician identify the bite as one of the venomous species.

 

The vast majority of bites don't need treatment and will heal on their own. Washing the bite area with soap and water is recommended to prevent infection; in some cases, an antibiotic ointment may be used as treatment. If there is pain and/or swelling, analgesics and/or anti-inflammatory drugs may be administered; if these cannot be administered, a cold pack for 15 minutes every hour may be applied to relieve the symptoms. If it becomes infected or develops into a skin ulcer, it should be treated with antibiotics.

 

If the bite is from a black widow spider, there is an antivenom that can be administered intravenously. It must be administered under medical supervision as it can cause severe allergic reactions.

 

Black widows tend to live in yards, barns, woodpiles, behind flowerpots, etc. It is also common to find them in unused closets.

 

The brown recluse lives in attics and basements where shelters and less used closets can be found.