Understanding the Dangers of Spiders in Your Home
Globally, only a handful of spider species have venom that is potent enough to cause serious health problems for humans. The risk to humans at home comes from these spiders living in proximity and being accidentally encountered.
Black Widow Spiders: These spiders are easily identifiable by their shiny black body and the distinctive red or orange hourglass-shaped marking on the underside of the abdomen (found on adult females). They are often found in dark, undisturbed areas like garages, sheds, basements, and behind furniture. A bite from a black widow can cause severe muscle cramps, intense pain, nausea, and vomiting. While bites are rarely fatal, they can be particularly dangerous for small children and the elderly.
Brown Recluse Spiders: Also known as "fiddleback" or "violin" spiders due to the dark, violin-shaped marking on their heads, these spiders prefer dry, sheltered areas. Indoors, they seek out dark closets, attics, and unused shoes and clothing. Their venom is cytotoxic, meaning it can cause the death of cells and tissue. A bite can result in a painful lesion that may develop into a large, open sore that can take months to heal.
Hobo Spiders: Found primarily in the Pacific Northwest of the United States, hobo spiders build funnel-shaped webs in dark, moist areas like basements and crawl spaces. Their bites can cause localized red swelling and pain, but are not known to cause the same necrotic lesions as a brown recluse bite.
Australian Funnel-Web Spiders: Native to Australia, these are among the most dangerous spiders in the world. They are not common in most homes, but can sometimes be found in basements or other sheltered areas. A bite from a male funnel-web spider is a medical emergency and can cause a range of severe symptoms, including profuse sweating, nausea, muscle twitching, and difficulty breathing.
How Spider Bites Occur and What to Do
Spider bites often occur when a human inadvertently comes into contact with a spider that feels trapped or threatened. For example, a person might put on a shoe or an article of clothing where a spider is hiding, or reach into a dark corner of a closet or garage. Most spiders are not aggressive and will try to flee rather than bite.
Symptoms of a Bite:
Most spider bites are harmless and cause only minor symptoms like redness, swelling, and localized pain, similar to a bee or mosquito bite. However, a bite from a dangerous spider can cause more serious symptoms, including:
Increasing pain over several hours.
A wound with a pale center that turns dark blue or purple with a red ring around it.
Fever, chills, body aches, or a severe headache.
Severe muscle cramping or abdominal pain.
Allergic Reactions:
In some rare cases, an individual may have a severe allergic reaction (anaphylaxis) to spider venom, regardless of the species. This is a medical emergency that can be fatal and requires immediate medical attention. Symptoms of anaphylaxis can include difficulty breathing, a swollen tongue, swelling of the throat, and dizziness or collapse.
What to Do if Bitten:
If you suspect you have been bitten by a spider, especially a black widow or brown recluse, it's crucial to seek immediate medical attention. If possible, safely collect the spider to help with identification. In the case of a severe allergic reaction, call emergency services immediately.
