Authors: Susan Wingate
Bites by spiders in this family can produce symptoms ranging from minor localized effects, to severe dermonecrotic lesions, up to and including severe systemic reactions including renal (that means kidney) failure, and in some cases, death, which in my estimation can never be really good.
Even in the absence of systemic effects, serious bites from Sicariidae spiders may form a necrotising ulcer (open weeping puss-producing sore. Gag.) that destroys soft tissue and may take months and very rarely years to heal, leaving deep scars. The damaged tissue may become gangrenous (this just keeps getting worse, doesn't it?) and eventually slough (like leprosy) away. OMG.
Initially there may be no pain from a bite, but over time the wound may grow to as large as 10 inches big! And, can you imagine walking around with a sore that big on your face or hand or calf! People would barf if they saw that.
Bites usually become painful and itchy within 2 to 8 hours, pain and other local effects worsen 12 to 36 hours after the bite with the necrosis developing over the next few days. And, no, a little neosporin isn't going to help so get your cadaver to the ER lest the side of your head falls off.
Serious systemic effects may occur before this time, as the venom spreads throughout the body in minutes. Mild symptoms include nausea, vomiting, fever, rashes, and muscle and joint pain. Rarely more severe symptoms occur including hemolysis, thrombocytopenia, and disseminated intravascular coagulation. Which I don't know what any of those mean but it sounds like they're not good things. Debilitated patients, the elderly, and children may be more susceptible to systemic loxoscelism. Deaths have been reported for both the brown recluse and the related South American species L. laeta and L. intermedia. Those six-eyed sand spiders. Heeby jeeby time, if ever.
Numerous other spiders have been associated with necrotic bites in the medical literature. Examples include the Hobo spider and the Yellow Sac spider. However, the bites from these spiders are not known to produce the severe symptoms that often follow from a recluse spider bite, and the level of danger posed by each has been called into question. So, if you're up for a test? Find one and let it bite you then report it to the wise and oh-so knowledgeable AMA. I'm sure they would like to know. You can assist them in their research.
So far, no known necrotoxins have been isolated from the venom of any of these spiders, and some arachnologists (a suspicious lot, known for siding with spiders--think defense attorney) have disputed the accuracy of many spider identifications carried out by bite victims, family members, medical responders, and other non-experts in arachnology.
There have been several studies questioning danger posed by some of these spiders. In these studies, scientists examined case studies of bites in which the spider in question was positively identified by an expert, and found that the incidence of necrotic injury diminished significantly when "questionable" identifications were excluded from the sample set. Which makes me question the word "questionable"--a Scooby moment, if ever.
It is often asked (by whom, one might wonder) which type of spider is the most "dangerous" in the world. I'm thinking, they should develop some sort of World Wide Wrestling match for spiders. There isn't a simple answer to this question, as there are many things which must be taken into account when considering the amount of danger posed by spider bites:
Firstly, it is often the case that a spider bite is "dry" – the skin may be pierced, but little or no venom is injected into the victim. In such an instance, little or none of the spider's dangerous potential for harm is manifested. It's like when your nose gets stuffy and you have to breathe through your mouth and your tongues gets all dry. Asky yourself, "If I bit someone right now, would it leave saliva or not? NOT! Which leads me to believe, now, that spiders get stuffy noses too.
Secondly, there have been reports of spider bites (by spiders considered otherwise harmless)--it's amazing these spiders write these reports themselves, isn't it? Thus, causing allergic reactions in some individuals, up to and including anaphylactic shock, a life-threatening condition (much the same as a sting from an ant, bee, or wasp may produce a harmful effect apart from the toxic quality of its venom).
Thirdly, many spiders listed as dangerous are seldom encountered (Phew!), or have dispositions (a more laid back chamomile-drinking group) that make them unlikely to bite despite the high toxicity of their venom.
Finally, little is known about the toxicity of many spiders, due to their infrequent encounters with humans; the list of venomous spiders is limited to those that are linked to medical events in humans or who otherwise have been extensively studied.
It should also be noted that, for healthy adults, a bite by even the most toxic spiders on the list may require hours before death ensues--in order for you to have the time to count your blessings; if timely appropriate emergency medical treatment is administered, victims may be expected to recover. The scenario given in movies such as Arachnophobia, where bite victims die within minutes, does not occur. One exception to this picture occurs because in the case of very small children the amount of venom dispersed throughout the body is many times the concentration in an adult. There is at least one recorded case of a small child dying within 15 minutes of a bite from a Sydney funnel-web spider; that event occurred before the development of an antivenom. Since the antivenom was developed there have been no fatalities due to this species.
The spider-bites documented as the most dangerous to humans are those of the Sydney funnel-web spider and the Brazilian wandering spider (but he's usually off galavanting somewhere else). These spiders are potentially more dangerous than widow spiders because they have longer fangs and can inject greater quantities of venom to greater depths. Egad. Phoneutria nigriventer (huh?) has approximately 2 mg of venom, but frequently gives dry bites or at least does not deliver all of its available venom. Atrax robustus (I can pronounce this one) has approximately 1.7 mg of venom. Bites of Six-eyed sand spiders have been described as dangerous to humans, but there is a lack of proof for this, though Sicarius venom has been shown to be fatal to rabbits. Poor little lab bunnies. :(
The genus Latrodectus (of which the black widow spider is the most notorious) have been credited with killing more people per year, worldwide, than any other spider. Because they are not very large, they are much harder to detect than a large Brazilian wandering spider or a tarantula. Their venom is extremely potent. Compared to many other species of spiders, their chelicerae are not very large. In the case of a mature female, the hollow, needle shaped part of each chelicera, the part that penetrates the skin, is approximately 1 mm (0.04 in) long, sufficiently long to inject the venom to a dangerous depth. The males, being much smaller, can inject far less venom and inject it far less deeply. The actual amount injected, even by a mature female, is very small in physical volume. When this small amount of venom is diffused throughout the body of a healthy, mature human, it usually does not amount to a fatal dose. Deaths in healthy adults from Latrodectus bites are rare in terms of the number of bites per thousand people. Only sixty-three deaths were reported in the United States between 1950 and 1989 (Miller, 1992). This is like 1.5 deaths per year from the Black Widow!
On the other hand, the geographical range of the widow spiders is very great. That means they are EVERYWHERE! SHRIEK! As a result, far more people are exposed, worldwide, to widow bites than are exposed to bites of more dangerous spiders, so the highest number of deaths worldwide are caused by members of the genus Latrodectus. Widow spiders have more potent venom than most spiders, and prior to the development of antivenin, 5% of bites resulted in fatalities, although comparable figures are not available for the other species.
It's a totally bogus grade.
TEN - Cats Make Good Company
My visits with Morlson became sort of boring. I mean, how many times could a girl bite her teacher on the leg without getting a bit sick of it? Not that many. Not with
In fact, I was starting to think about bagging the whole visitation hoo-ha, when the playing field changed.
Say, like you're minding your own business and someone sneaks up behind you and, Kablowee!
You jump out of your Shape-Ups and hit your head on the ceiling.
Kind of like that but with insects.
My cover had been compromised!
till, I thought it was a sneaky move on my part.
That it would... drive... Morlson...
That it would be fun to watch her go absolutely nutball insane.
What a dork!
Pussy and I had brought the pic of my teeth, cropped, of course to conceal my true identity. I rolled it up and slipped it through a jerry-rigged collar for pussy I'd created out of printer paper so, that if she got it snagged on something, bam! It would snap off without strangling her to death.
Without pussy by my side, I'd be so depressed.