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Desert Brown Recluse

Discussion in 'Other Spiders & Arachnids' started by Irene B. Smithi, Aug 9, 2009.

  1. Venom

    Venom Arachnoprince Old Timer

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    Excuse me?

    Link one was from the U. S. National Library of Medicine / National Institutes of Health.

    Links two and four were written by nationally-recognized physicians.

    Link three was from the American Journal of Arachnology

    Link four was from the American Journal of Tropical Medicine and Hygiene.

    Your stunning idea that Loxosceles do not/ can not cause human fatality is completely contrary to these reputable sources! You are basing this on your IMPRESSION that recluse spiders "aren't that bad," based on their normally inoffensive behaviour. I'm sorry, but that is an entirely subjective, baseless, and ignorant presumption. The three major South American Loxoscelids, L. laeta, intermedia, and gaucho, have a 13% incidence of systemic effects, and a 1.5% incidence of FATALITY. Documented by science! In the medical literature! Are you honestly going to say "pff, they all just guessed it was Loxos...cuz I don't think..blah blah" ???

    Loxosceles is a highly toxic genus, which, on rare occasion, HAS killed. To deny this...you'll have to contradict CEVAP, the National Institutes of Health, and many other reputable sources that all say Loxo spp. can be life-threatening on occasion.

    And please, don't post another pic of you handling a Loxosceles, and cite that as proof that they aren't dangerous. That only proves how dumb you are and how docile the genus usually is--nothing to do with toxicology or medicine. Your subjective, uniformed opinion is contra-factual, and quite frankly, a dangerous encouragement to others to be less careful than they ought.

    Once again, I link you to an abstract to an article, provided by the NIH:

    "Report of fatality: spider bite (Loxosceles)" IMJ Ill Med J. 1970 Apr;137(4):339.

    http://www.ncbi.nlm.nih.gov/pubmed/4393470
     
  2. buthus

    buthus Arachnoprince Old Timer

    And why cant I say that? ...to question it? 1.5% of these mysterious spiders bites caused deaths? Maybe ...but oh...thats right...dont question authoritative medical science. :clap:

    And I never said that they couldnt cause problems ...YOU just want to make sure everyone knows they are dangerous AND I just wanna make sure everyone knows they are not. Whos right? (btw...laugh smiles @end of a post usually means "read w/sense of humor" ...or "dont take this seriously" ...but i do apologies if you thought I was truly dis'n yer post/info)

    Now ...as for handling to demonstrate this... what does showing that they are mostly harmless have to do with their venom? They are NOT something to worry about ..period. Ill post whatever images I choose to and that are deemed appropriate for this forum.
     
  3. What

    What Arachnoprince

    Those are presumed bites, unless the person was observed by someone experienced with spiders being bitten by a Loxo, and then immediately started showing symptoms, it would be foolish to assume that is is definitely from the venom. When I met Rick Vetter(the self-proclaimed expert on Loxosceles and author of a number of papers on the spiders), he admitted the possibility that the effects of the "venom" might just be a result of bacteria residing on the chelicerae after having scavenged from carrion(and that not all venom comp. studies showed sphingomyelinase D as a component). Have a look at some of the other causes of necrosis and then check to see that all those papers you are citing ruled them all out... :)
     
  4. Thank you so much for all your information, I've spent the day looking over it. Thank you for your sources, it's been a lot of informative reading.
    I've learned a lot about them, almost more then a mom would want to know!!! It's good to know that they tend to be docile, but their still very scary. However the more I learn about these little guys the better I sleep.
    Thank you for your time and effort.



     
  5. Venom

    Venom Arachnoprince Old Timer

    And to a novice, that has the sound of plausibility. But tell me, how does a superficial bacterial infection cause the systemic cytotoxic effects observed in the cardiovascular system and beyond: masses of popped red blood cells, swelling of the liver, renal failure, aneurism, coronary occlusions? Sicarius is deadly because it has amped up concentrations and quantities of Sphingomyelinase-D. Loxosceles is just the little brother to Sicarius, and has the same proteolytic enzyme in its venom, just to a lesser extent.

    The deaths caused by Loxosceles spp. were caused by the SYSTEMIC effects noted above, NOT by the gaping wound. A topical sore can be written off as bacteria, especially since the wound can become infected AFTER the fact, but systemic effects can not so easily be ruled an infection! Blood / urine tests would show the presence of bacteria in an otherwise sterile environment. Blood and urine are sterile. The typical cause of death from Loxosceles is renal failure, which is caused by the kidneys becoming jammed up with dead blood cells. There is blood in the urine, which becomes red/ black. Now, this is caused haematuria, and is a sign also of renal infection, which is easily checked for by culturing the urine. You don't think the doctors tending these cases thought of that?? You don't think they checked patients dying of kidney failure, to see if they had a simple kidney infection?? Sorry, your position of it being bacterial does NOT stack up. If they had haematuria, and yet their urine and blood were sterile, there could be no infection of either blood or urine---the haematuria would have HAD to be caused by a non-bacterial agent. This is simple medicine, and the doctors tending these cases of L. laeta, intermedia, and gaucho deaths, KNOW all this.

    Even if a physician did not have proof, or even a report, of a spider being the culprit, they could easily rule bacteria OUT by testing internal fluids. Topical wounds are what get mistaken for infections, but they are not the cause of Loxo-related death. What kills, is easily determined to be the action of a toxin/ venom, rather than a pathogen.

    Sorry Buthus/ What, but that 1.5% mortality is from internal, not external Loxoscelism. The statistic is reliable.
     
    Last edited: Aug 10, 2009
  6. Nomadinexile

    Nomadinexile Arachnoking

  7. What

    What Arachnoprince

    Did you read the list of things that cause necrosis? Did you look to see which of those are also actively producing sphingomyelinase D?

    In 20 mins of looking around I have found 3-4 fungi that produce it(and are known to infect humans), a handful of bacteria known to have caused deaths in humans, and two types of allergic reactions that cause both necrosis and widespread systemic effects(Eurythema multiforme and Stevens-Johnson syndrome). Some of these also cause the widespread systemic cytotoxic effects, just because bacteria/other things are unlikely to cause the same things or death does not mean it is not possible or even more probable than death from a Loxosceles bite.

    Venom, you seem awfully consumed by a need to fear monger. Nobody doubts that in some cases Loxos can be dangerous, but we also should not discount that compared to even the flu the chances of death are slim to none, even without taking into account the unlikelihood of being bitten and having any reaction at all. Do we all really need to bring up the paper about the ~2000 loxos collected in a family's home in Kansas without any bites/effects suffered from a bite that was not felt/noticed? And that was L. reclusa, not one of the other species that are not even known to be medically significant like the ones found around Vegas(likely L. deserta).
     
  8. jsloan

    jsloan Arachnoangel Old Timer

    What and Venom: Do either of you have any medical or scientific background/training? Just wondering.
     
  9. Venom

    Venom Arachnoprince Old Timer

    Yes. In addition to the enormous amount of reading I have done on this, and many other scientific subjects, I have 21 college credits in the natural sciences, in addition to the sciences (Chemistry, Biology, Physics) that I studied in high school.
     
    Last edited: Aug 10, 2009
  10. jsloan

    jsloan Arachnoangel Old Timer

    What natural sciences?
     
  11. Venom

    Venom Arachnoprince Old Timer

    8 credits of chemistry, also geo-sciences and mathematics.

    Not that its a terribly relevant question. Arachnoculture is an amateur pursuit for me, though I do take it seriously. I've spent the last 10 years studying arachnid venoms and envenomations in my free time. In that decade, I think I have become knowledgeable enough to deal with complex issues such as identifying viscerocutaneous loxoscelism, and evaluating the effects of the various cytotoxic araneids. I'm not an arachnologist, but I would assert that I know the specific issue of envenomation ( as opposed to issues like taxonomy, ecology, anatomy of arachnids ) better than most arachnologists do. As an historian, I have significant training and practice with the analytical process, evaluating evidence scenarios, connecting the dots in regard to issues that I cannot directly observe, and I feel that these skill serve well even in the pursuit of discussing arachnid envenomations.

    I have done a fair bit of identifying bites on the internet, and I stand by my identifications, as well as the assessments of seriousness which I give to the various forms of envenomation arachnids can present. I have done a great deal of reading in the medical literature, as well as arachnology sources, and I am in the majority when I posit that L. reclusa and its relatives, are NOT an acceptable "common house spider," but, despite their usually benign behaviour, a real and serious issue.

    Contradict me if you like, but you'll have to address the --very-- credible sources I gave above.
     
  12. jsloan

    jsloan Arachnoangel Old Timer

    I agree with you about Loxosceles venom.

    No, I was just asking. Based on what you've written in this and other threads, on a variety of subjects, your scientific training and knowledge seems to be about where I thought it was.
     
  13. Venom

    Venom Arachnoprince Old Timer

    Oh ok. I wasn't sure what your reason for asking was.

    I'm not sure exactly what you mean by that. While I don't have gobs in the way of formal training, I'm an avid science reader, particularly in physics. I try to stay abreast of developments in relativity, astrophysics, and theoretical physics, for example, through a number of journals and publications. I consider myself a scientifically minded, and fairly well-informed person. My college credits, while providing me with a platform of familiarity with scientific concepts and procedures, do not reflect the extent of my knowledge. I've done much more on my own to educate myself in the natural sciences. Arachnoculture, like I said, is a hobby of mine which I take seriously. I do know what I am talking about in these venom threads.

    But thanks for agreeing with me on the Loxosceles venom. I really don't get why people nay-say their toxicity.
     
    Last edited: Aug 10, 2009
  14. Nomadinexile

    Nomadinexile Arachnoking

    This is one example of many I have found along these lines...I don't know much of anything about this, but I have found seemingly reasonable arguments for it. I don't have a big science background though. I mostly like hunting scorpions or just being in the woods. :)

    "It has recently been questioned by many investigators that a spider bite can be the cause of severe necrosis."

    Found here: http://www.xs4all.nl/~ednieuw/Spide...emystification of the toxicity of spiders.pdf


     
  15. What

    What Arachnoprince

    Medical no, other than spending an inordinate amount of time with doctors the past 4 years(medical problems).

    Scientific, I have taken all the bio/ecology/natural history classes at my local community college and I have read numerous scientific papers on arachnology/inverts in general. I also am close friends with a couple professional entomologists and I have been told by numerous professors at my school and in my area that I am "quite possibly the most well read and experienced amateur entomologist/arachnologist in southern California," but that doesnt really mean much at all(as there are admittedly huge gaps in my knowledge).
     
  16. pandinus

    pandinus Arachnoking Old Timer

    i dont naysay the fact that L reclusa has a potentially potent venom that can in some cases be very dangerous and occasionally deadly. but i will say this. this is not even the same species as the one the OP has in her yard, which is most likely the much less dangerous L deserta. secondly i have lived in KS for 19 years and have shared my house with hundreds upon hundreds upon thousands of L RECLUSA, the more dangerous species for the entire time. they frequently appear in my bedroom, bathroom, hallway, shower, etc. it is more common for me to find them indoors than outdoors. most homes are this way in the midwest as they infest 70% of homes in the midwest (and know i dont live in a little podunk town of 14 people and 2 cows i live in the city) i have only ever recieved one bite from this species when i was around 8 years old. it produced a little sore that opened up into a little ulceration about the size of a pea, and then scabbed up and healed over leaving a little tiny scar on my chest right above my sternum. the chances of being bitten at all are extremely low, even in a house with a population of them numbering 100+ they are very reclusive and even when cornered almost refuse to bite i step on them with bare feet regularly most of the time by accident. in the RARE event that through some freak occurence you manage to get bitten, the chances of a bite producing much more than a little sore that will blister up and heal over in a week or two is very low, and the chances of a dangerous reaction are even less. therefore it seems to me that given the compound of these facts plus the fact that the species you are finding is widely considered to be much less toxic than the one here, you have just about as much chance as having a reaction like those described by venom as you do being attacked by a wild dog or struck by lightning. they deserve respect but not fear.



    John
     
  17. jsloan

    jsloan Arachnoangel Old Timer

    Thanks for the reply. I often wonder about how much people know in a forum like this, especially when the subject is technical and arguments are flying back and forth. That's why I asked. I'm not judging either one of you.

    Turnabout is fair play: I've had a couple years of entomology in the 70s, and the usual high school science classes. I am currently enrolled in the 4-year general science degree program at Athabasca University, and may try to do some graduate work or go for a masters after I get my BS degree. Have done lots of the usual technical reading on arachnology in journals, etc. My main interest in arachnology is spider physiology and behavior. I want to find out how they live their lives, and what makes them tick.

    As always, in subjects/threads like this, I think verified data or experimental results are the only things that really count. In this case, verified data would be bites in which the spider was collected and identified (by a qualified arachnologist) and linked, without question, to the bite - and the bite reported on by an MD. Probable bites, or bites attributed to spiders only on the basis of examining the wound and nothing else (that is, without ever having seen the spider), do not count, IMO.
     
    Last edited: Aug 11, 2009
  18. jsloan

    jsloan Arachnoangel Old Timer

    What is "arachnoculture"? I've never heard of that term before.
     
  19. buthus

    buthus Arachnoprince Old Timer

    1.5% of just about everything causes death.
    And even if there is a chance that loxo venom can cause problems ...big deal. 1.5% death rate vs more idiots making money poisoning our homes and land... ill take the high road and say I dont care. Long term affects are what we should be concerned with.
    I say peanuts are NOT acceptable party snack food ...crap should not even be allowed in the house.
     
  20. cacoseraph

    cacoseraph ArachnoGod Old Timer

    Peanut would be most distressed to hear that from you!
     
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