# Tarantula venom causes paralysis in humans?



## dragonblade71 (Sep 6, 2007)

I was reading a website which described possible symptoms that one could obtain from a tarantula bite and one of these was paralysis! The website does state that this would be temporary. Other symptoms mentioned were myonecrosis and 'localised death of muscle cell fibres.' I have read various sources which mention symptoms that would likely result from tarantula bites though I have never come across these particular symptoms described before. I must say that these symptoms sound quite severe. 

I am planning to obtain an Australian tarantula which are usually known to inflict the worst symptoms of any tarantula bite. If I am unlucky to get bitten oneday, I am hoping that I won't experience any of the symptoms mentioned above (but I do expect that I'll have to put up with the usual pain and swelling and possible nausea.) Can any of the knowledgeable board members here confirm whether the symptoms described from the website are really plausible in regards to tarantula bites?

This is the site below which describes the possible effects of bites. 

http://www.tarantulatour.com/thebite.html


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## Rochelle (Sep 6, 2007)

I'm told that Pterinocilous murinas will cause muscle tremors; so the especially nasty Australian T's would seem to be the best candidate for temporary muscle paralysis. Logical conclusion.  Maybe you'll get lucky and one of the REAL experts will be able to answer your Q.  It's a good one, considering that more of these "wonderful nasties" are being shipped and sold here.....  The answer will benefit us all.


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## DrAce (Sep 6, 2007)

dragonblade71 said:


> I was reading a website which described possible symptoms that one could obtain from a tarantula bite and one of these was paralysis! The website does state that this would be temporary. Other symptoms mentioned were myonecrosis and 'localised death of muscle cell fibres.' I have read various sources which mention symptoms that would likely result from tarantula bites though I have never come across these particular symptoms described before. I must say that these symptoms sound quite severe.


The magic words in that website are all there "Could" and "might".


			
				Tarantula Tour said:
			
		

> The effect on a healthy human could range from a rash to temporary symptoms of paralysis to the affected area and myonecrosis; localized death of muscle cell fibers.


For clarification, myonecrosis IS death of muscle fibers, localized or otherwise.  Myo means muscle, and necrosis means death.

I think you're better to look for actual reports from the species you are interested in.  There is a great resource here on the boards - the bite section, and, to my knowledge, no-one has reported myonecrosis.

The site is right, however, the real danger comes if you are alergic.  I doubt myonecrosis would result, but you may stop breathing -and that does lead to myonecrosis!

There are spiders which will cause necrosis -the recluse and the hobo are amongst them (although some argue that this is a consequence of secondary infection, not the bite).

I am of the understanding that most tarantula bites are immune responses more than anything else - something an anti-histamine will take care of.  The Australian Funnel Web, however, will also cause necrosis followed quickly by death.

All data from "Color atlas of human poisoning and envenoming" by James Diaz, CRC Press, 2006: ISBN 0-8493-2215-4


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## Moltar (Sep 6, 2007)

Take some time to browse the bite reports. They can be pretty entertaining in a sadistic sort of way. The "paralysis" actually experienced w/ P murinus were more like tremors, bad muscle aches, spasms, etc. The scariest one i saw was labored breathing like someone was pressing down on their chest. Presumably from partial paralysis of the diaphragm muscle. Eeeks!


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## Scott C. (Sep 6, 2007)

DrAce said:


> ...The site is right, however, the real danger comes if you are alergic.....


Hey Doc,
I was under the impression that alergic reactions to T venom don't happen due to size of proteins/peptides, or some such scientific jargon... 

Has that changed, or was it wrong to begin with?


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## Crotalus (Sep 6, 2007)

Scott C. said:


> Hey Doc,
> I was under the impression that alergic reactions to T venom don't happen due to size of proteins/peptides, or some such scientific jargon...
> 
> Has that changed, or was it wrong to begin with?


No you were right.


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## dragonblade71 (Sep 6, 2007)

"I think you're better to look for actual reports from the species you are interested in."

Yea I have previously read the bite reports on the board for two cases of Australian tarantula bites. In one of these cases, the victim suffered some loss of vision which is a symptom that i have certainly never heard of before! The same person also reported that they lost sense of where they were after the bite occurred.


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## Crotalus (Sep 6, 2007)

DrAce said:


> The site is right, however, the real danger comes if you are alergic.  I doubt myonecrosis would result, but you may stop breathing -and that does lead to myonecrosis!


You cannot suffer severe allergic reaction due to the venom components that in spider venom are very different from for example snake or bee venom (that readily cause anaphylaxis)
This is not my words but toxinologist Bryan G Fry.



DrAce said:


> I am of the understanding that most tarantula bites are immune responses more than anything else - something an anti-histamine will take care of.  The Australian Funnel Web, however, will also cause necrosis followed quickly by death.


See above.
The funnel web venom are neurotoxic with no local necrosis (in Atrax envenomations) - perhaps species in Hadronyche cause local necrosis but its the least of worries if bitten by one.


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## Moltar (Sep 6, 2007)

dragonblade71 said:


> "I think you're better to look for actual reports from the species you are interested in."
> 
> Yea I have previously read the bite reports on the board for two cases of Australian tarantula bites. In one of these cases, the victim suffered some loss of vision which is a symptom that i have certainly never heard of before! The same person also reported that they lost sense of where they were after the bite occurred.



Yeeeowch!!! that's pretty hardcore.

Yaknow... there are people on here that keep deathstalker scorps, rattlesnakes, vipers, widows, etc. Those guys have balls. Big solid steel bulletproof balls that i apparently do not (ladies please apply your organ of choice in place of the afore mentioned balls) Maybe it's because of my little nephews always visiting and maybe it's because i'm just plain scared but i don't want any critters in my house that could potentially kill or permanently disable or disfigure someone. Nothing against those of you that do of course. I guess y'all are just more confident in your husbandry skills or whatever. Hat's off to ya!

I'll stick w/ my fair-to-middlin toxicity bugs, thank you.


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## Rochelle (Sep 6, 2007)

Bosh!  Come to a Detroit rock concert. All the same symptoms can be experienced - without a Tarantula in sight....lololol   PARKING - now THAT'S deadly! ;P


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## Venom (Sep 6, 2007)

> Can any of the knowledgeable board members here confirm whether the symptoms described from the website are really plausible in regards to tarantula bites?


Whatever report you read, it was way overblown.

Tarantula venom will not cause significant necrosis, or even Cheiracanthium-level necrosis, no matter what the species. They simply lack the cytotoxic or hemolytic components to make this happen. The only way a tarantula bite *MIGHT* cause ANY notable tissue death is if swelling occurred to the extent that it cut off circulation. I am aware of one case that _almost _had an amputation for Poec-induced swelling, but this was more a case of incompetent doctors than a good treatment option. Severe swelling can result from Poecilotheria, Pterinochilus, and a few other genera, but the number of cases causing circulation-_stopping _swelling would be measured in thousandths of a percentile. 

As for paralysis, not likely. The only systemic paralysis case I know of was from P.striata, and it wasn't true paralysis. What happened was that, whenever the subject tried to move, all his muscles cramped and seized up--making him, practically speaking, unable to get off his bed. However, he was technically still was able to engage his muscles. As for local paralysis/ stiffness --yeah, ok. Sometimes people nailed by a pokie can't use their hand for a while. But I get about the same whenever I slam a finger/hand in a car door or hit it with a hammer.

Australian tarantulas are among the more potent T's, but that isn't saying much as far as toxic inverts go. There are no deaths, and you won't be paralyzed. What you might get from a strong ( above average ) bite, could include dizziness, muscle cramping, confusion, pain, nausea--that sort of thing. As always, it's a question of what you feel comfortable dealing with. If you feel you can keep yourself safe, and the risk is acceptable, then go for it. If not, there are loads of other species out there! Just keep what you can safely enjoy.




> but I do expect that I'll have to put up with the usual pain and swelling and possible nausea.)


If you're up for that, you're probably ready for an Aussie. Just treat them with the respect you'd give a pokie.


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## Scott C. (Sep 6, 2007)

thanks Lelle.


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## DrAce (Sep 6, 2007)

Crotalus said:


> You cannot suffer severe allergic reaction due to the venom components that in spider venom are very different from for example snake or bee venom (that readily cause anaphylaxis)
> This is not my words but toxinologist Bryan G Fry.
> 
> See above.
> The funnel web venom are neurotoxic with no local necrosis (in Atrax envenomations) - perhaps species in Hadronyche cause local necrosis but its the least of worries if bitten by one.


With all due respect, Crotalus, I beg to differ.  From Bryan G. Fry's own website:

"_Spider venom peptides
Mu-Agatoxins
The nomenclature of spider peptidic neurotoxins is, unlike that of scorpions, based on the same convention as that of cone-snails and snakes: alpha-toxins inhibit the acetylcholine receptor; mu-toxins directly abolish muscle action potentials through the inhibition of muscle sodium channels; and omega-toxins prevent voltage-activated entry of calcium into the nerve terminal and the release of acetylcholine.

Spider mu-toxins are cysteine-rich polypeptides, which cause irreversible paralysis and repetitive action potentials originating in presynaptic axons or nerve terminals. Clinical effects of a bite from one of the North American funnel web-spider Agelenopsis aperta are negligible. The venom, however, has yielded several interesting peptides that have pharmacological properties that may prove to be quite useful. Two specific mu-agatoxins have been identified from A. aperta, mu-agatoxin-I and mu-agatoxin-IV, both of which contain *36 amino acids* and four internal disulfide bonds. Although these toxins specifically modify voltage-sensitive sodium channel activity, they have structural similarities with a plethora of other peptide toxins targeting a myriad of channel types. Analysis of these variations may shed light not just on functional residues of the particular scaffold but also provide data as to the structure and specificity of the binding sites of the channel being affected. This adds to the emerging wealth of data of a common scaffold being modified for divergent use.

The omega-agatoxins from A. aperta consist of two subtypes of neuronal calcium channel toxins with different structural characteristics and binding specificities. Type I agatoxins, such as omega-Aga-I, may define a binding site on neuronal calcium channels that is common to both vertebrates and invertebrates. Type II omega-toxins, such omega-Aga-II, III and IV, share limited amino acid sequence similarity with Type I toxins. However, omega-Aga-IVA is able to block omega-CTX-GVIA (Conus geographus) resistant calcium channels. This use of structurally distinct toxins from common as well as divergent sources is an excellent manner in which to study a channel.


The peptidic neurotoxins from A. aperta have similar locations of cysteine residues with neurotoxins from the venom of another North American funnel web spider Hololena curta as well as neurotoxins from the more distantly related Brazilian spider Phoneutria nigriventer (Wandering spider). This conservation of structure among these three species is interesting to view from a taxonomic standpoint in that venom peptide sequences may be useful as chemotaxonomic tools. Despite being the only lethal species amongst the three spiders, the toxins of the Phoneutria nigriventer share strong structural similarity, particularly in the location of the cysteine residues with neurotoxins from these other two spiders.

While the lethal neurotoxin PhTx1 from Phoneutria nigriventer venom has a primary structure shows no homology to any other identified spider toxin, cDNA libraries constructed from the venom glands revealed that the structure of the preprotoxin initially synthesized by the Tx1 gene shows similarity in sequence and also in processing with the synthesis and processing of omega-agatoxin IA from A. aperta. Thus, this toxin may not be quite so unrelated but rather may represent a case of a spider that is taxonomically divergent, as P. nigriventer is from the more closely related two N. American species, with the venom diverging along with it.

Delta Atracotoxin
Unlike the American funnel web spiders, the venoms of Australian funnel web spiders are quite lethal, consisting of a large number of acute acting neurotoxins. These venoms slow the inactivation of primate sodium channels causing envenomation symptoms involving pain at the bite site, salivation, lachrymation, piloerection, generalized skeletal muscle fasciculation, sweating, nausea, vomiting, diarrhea, pulmonary edema, dyspnoea followed by respiratory failure, tachycardia and hypertension followed by hypotension and circulatory failure.

The primary toxic components of the venoms of two species have been isolated and characterized. The lethal toxins from A. robustus and H. versuta venoms are the *42 amino acid peptide* components robustoxin (atracotoxin) and versutoxin respectively. Versutoxin differs from robustoxin by only 8 amino acid residues. Disulfide-bridged cysteine residues at both the amino- and carboxy-termini and a triplet of cysteines at residues 14-16 makes these components unprecedented amongst neurotoxins_"


He knows his stuff, however he mentions (in bold) several groups of peptides which are quite big enough to give you an immune response.  Unlikely, yes.  Possible, definately.

Do I have specific data for australian tarantulas, or indeed any other tarantulas of interest here?  No - just the book I reference above.  However, there is almost ALWAYS a potential for an allergic response.  The "Colour Atlas of Human Poisoning and Envenoming" mentions that the localised swelling from most bites is an immune/histamine type response, and I have seen nothing so far which would suggest otherwise.

Certainly, most spiders seem to employ the same tricks, which Dr Fry does include in the stuff above - that is to block ion channels; the stuff which keeps your brain ticking over.  Localised necrosis is also mentioned as a possible effect from some spiders.  I agree it's extremely unlikely, but it's there as a possibility!


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## DrAce (Sep 6, 2007)

Scott C. said:


> Hey Doc,
> I was under the impression that alergic reactions to T venom don't happen due to size of proteins/peptides, or some such scientific jargon...
> 
> Has that changed, or was it wrong to begin with?


See my most recent post above.  While some suggest that there is no possibility for an immune response, a 42 amino acid peptide is more than enough.  I've gotten antibodies from a peptide only a fraction bigger (45) in the lab.


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## Cirith Ungol (Sep 6, 2007)

It wasn't entirely ruled out in the previous long discussion about this topic either, but also deemed very unlikely.


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## DrAce (Sep 6, 2007)

Cirith Ungol said:


> It wasn't entirely ruled out in the previous long discussion about this topic either, but also deemed very unlikely.


I've not seen it, but it makes me feel slightly vindicated.

Can you post a link there?

Incidentally, Dr. Bryan Grieg Fry is kinda cute.  I recommend his site.

He does seem more of a snake venom guy than a spider venom guy - although both would trump my bumblings into the area.  I do know for a fact that 42 amino acids can give you an immune response.


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## Cirith Ungol (Sep 6, 2007)

DrAce said:


> I've not seen it, but it makes me feel slightly vindicated.
> 
> Can you post a link there?
> 
> Incidentally, Dr. Bryan Grieg Fry is kinda cute.  I recommend his site.


Not sure if you'll feel that vindicated after reading it, it was deemed so unlikely to almost being "impossible" so I guess we are landing in a zone of interpretation, at least regarding the old thread. 

Actually, I found two. I place them in cronological order:
http://www.arachnoboards.com/ab/showthread.php?t=54244
http://www.arachnoboards.com/ab/showthread.php?t=77826

Edit:
Wouldn't it be helpful for the sake of the discussion to make a distinction between localized allergic reaction and anaphylactic shock?


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## Crotalus (Sep 6, 2007)

Dr Ace, zero cases of anaphylaxis in the litterature (and there are no shortage of bite cases from those spider species) might give us a hint that we can rule it out.
So, unless someone provide documented cases I think its correct to say it doesnt cause it.

As you state yourself in your first reply here:
"The magic words in that website are all there "Could" and "might"." 

I choose to leave those words out and let facts speak for itself.


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## abarth (Sep 6, 2007)

This is a bit OT, but reading all this I come to yhink of, what harm can a tarantula-bite actually do to a small child?


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## DrAce (Sep 6, 2007)

Crotalus said:


> Dr Ace, zero cases of anaphylaxis in the litterature (and there are no shortage of bite cases from those spider species) might give us a hint that we can rule it out.
> So, unless someone provide documented cases I think its correct to say it doesnt cause it.
> 
> As you state yourself in your first reply here:
> ...


Again, Crotalus.  I'm not sure we're sparring AGAINST each other, as oposed to nit-picking...

However, we're not talking about everyone here.  We're talking about someone who has an alergic shock reaction - something which by definition is rare.  I, for one, would not like to say it's impossible, when there is a distinct possibility that it can happen.

A large chunk of the earth's population does not live in daily interaction with tarantulas - particularly the Australian species.  I doubt that there are a million people LIVING on earth who have been been bitten by one, and these sorts of severe reactions are likely to occur in less-than-one-in-a-million chances.

On top of all this, the venom is not a highly purified substance, to my knowledge.  There is a high chance that other proteins are present, any one of which are not-human, and therefore likely to induce a reaction.

Again, I agree it's unlikely, but saying "it's never happened" is like a Ukranian Engineer working for Chernobyl saying "it's never happened so far...".

Absence of evidence is not evidence of absence.

I completely and utterly agree that there is no reason to be concerned.  I don't lie awake at night, worried about getting tick-paralysis, and I will not be concerned about spider bites.  But the chances are there, and the logic behind the declaration that it's impossible is flawed.


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## Moltar (Sep 6, 2007)

I'll stay away from the anaphylactic shock debate other than to say i don't think you guys are comparing apples to apples. On the subject of necrosis: If i personally were bitten by a male sydney funnel web spider (latin?) i'd be thanking my lucky stars to still be alive in time for tissue necrosis to set in. The discovery channel told me you can die within an hour without antivenom.


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## DrAce (Sep 6, 2007)

etown_411 said:


> I'll stay away from the anaphylactic shock debate other than to say i don't think you guys are comparing apples to apples. On the subject of necrosis: If i personally were bitten by a male sydney funnel web spider (latin?) i'd be thanking my lucky stars to still be alive in time for tissue necrosis to set in. The discovery channel told me you can die within an hour without antivenom.


I think you're right.  Both Crotalus and I agree that this is not worth worrying about.  I merely have been told that the localised swelling is a local immune response, and that anti-histamines are usually effective in reducing it.  Who knows. I also maintain that it is possible (just possible) to have an alergic shock to something that a spider jabs into you, and those peptides are possible.  Not a medically significant problem.

You heard what I heard about the funnel web spider.  I've seen one in Sydney, and they're angry little buggers too.


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## Nitibus (Sep 6, 2007)

DrAce said:


> Absence of evidence is not evidence of absence.



Great now you'll tell me the loch Ness Monster and Big-foot do exist ! 


Isn't all science ( other than physics in most cases ) just assumptions that haven't been proved wrong ?  Science is a thoery with an absence of refutable evidence ? You can't refute what doesn't exist...like the Loch ness monster


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## DrAce (Sep 6, 2007)

Nitibus said:


> Great now you'll tell me the loch Ness Monster and Big-foot do exist !
> 
> 
> Isn't all science ( other than physics in most cases ) just assumptions that haven't been proved wrong ?  Science is a thoery with an absence of refutable evidence ? You can't refute what doesn't exist...like the Loch ness monster


Yes, although you can attach a likelyhood to some events.  Some evidence for the possibility of an immune response exists.  There is none for bigfoot of the loch-ness.


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## Crotalus (Sep 6, 2007)

DrAce said:


> Again, Crotalus.  I'm not sure we're sparring AGAINST each other, as oposed to nit-picking...
> 
> However, we're not talking about everyone here.  We're talking about someone who has an alergic shock reaction - something which by definition is rare.  I, for one, would not like to say it's impossible, when there is a distinct possibility that it can happen.
> 
> ...


Theres no sparring or nitpicking as far as I can see. 
I agree that you never know what future holds but as today nothing shows that severe allergic reastions is some thing that we have to worry about - I prefer to look at the facts what we do know and build my opinion from that. 
Tick diseases are a fact, allergic responses to tarantula venom is not - australian or not. 
Absence of evidence is a better indicator then "mights" and "coulds" in my book.


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## Moltar (Sep 6, 2007)

Ya. I thought you needed proteins for anaphalaxis to occur and T venom has peptides, not proteins. I didn't read all the quoting that was going on up there so maybe you covered it already.

Normally when i see a cool bug i make a beeline for it. (pun?, no...) but if i saw an angry SFW i'd scream like a little girl and run away. Can't imagine what it must be like having something that feisty and venomous be so common in an urbanised setting like that.


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## Nitibus (Sep 6, 2007)

DrAce said:


> Yes, although you can attach a likelyhood to some events.  Some evidence for the possibility of an immune response exists.  There is none for bigfoot of the loch-ness.




[YOUTUBE]6Ij6JL_dMNk[/YOUTUBE]

[YOUTUBE]D2wQn0ty6kg[/YOUTUBE]


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## Crotalus (Sep 6, 2007)

etown_411 said:


> I'll stay away from the anaphylactic shock debate other than to say i don't think you guys are comparing apples to apples. On the subject of necrosis: If i personally were bitten by a male sydney funnel web spider (latin?) i'd be thanking my lucky stars to still be alive in time for tissue necrosis to set in. The discovery channel told me you can die within an hour without antivenom.



Here you have bite records from funnel webs. Note the parts where they mention allergic reactions and necrosis:

http://www.inchem.org/documents/pims/animal/atrax.htm


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## DrAce (Sep 6, 2007)

etown_411 said:


> Ya. I thought you needed proteins for anaphalaxis to occur and T venom has peptides, not proteins. I didn't read all the quoting that was going on up there so maybe you covered it already.
> 
> Normally when i see a cool bug i make a beeline for it. (pun?, no...) but if i saw an angry SFW i'd scream like a little girl and run away. Can't imagine what it must be like having something that feisty and venomous be so common in an urbanised setting like that.


There is only one difference between peptides and proteins - size, but there is no threshold where one becomes the other.  A protein is a big peptide.

You CAN get an immune response from a small peptide.  There are even studies (Thoth posted some in a posting referenced above) where there is evidence of elevated immune markers after a bite.

I.e.  it's possible, and all the markers are there.

ANY time there is an immune response, there is the possibility of it going to allergic shock.  That, unfortunately, is a fact.


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## DrAce (Sep 6, 2007)

Nitibus said:


> [YOUTUBE]6Ij6JL_dMNk[/YOUTUBE]
> 
> [YOUTUBE]D2wQn0ty6kg[/YOUTUBE]


I see nothing to allow the possibility of a giant humanoid or an ancient monster.


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## Nitibus (Sep 6, 2007)

DrAce said:


> ANY time there is an immune response, there is the possibility of it going to allergic shock.  That, unfortunately, is a fact.


That being said, since urticating hairs are a immune response. Then it should be possible for people to go into allergic shock from urticating hairs ? Is that correct ? 

PS. I'm no scientist 


P.S.S. I'll stop goofing around with big foot now


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## DrAce (Sep 6, 2007)

Nitibus said:


> That being said, since urticating hairs are a immune response. Then it should be possible for people to go into allergic shock from urticating hairs ? Is that correct ?
> 
> PS. I'm no scientist
> 
> ...


Theoretically, yes.  Although that would be initially slower.

Here is a paper indicating the suspected Anaphylaxis from caterpillar hairs.

This site (medical in nature, but not one I've seen before), indicates about half way down that anaphylaxis is known from hairs.


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## Crotalus (Sep 6, 2007)

Atleast the local reaction are similar 
If you inhale them I would think the swollen throat is a result of the hairs location

edit: Note the article says the word "*may*" - not "have"  so no evidence here either for anaphylaxis really occured. Just assumtions.


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## Scott C. (Sep 6, 2007)

Thanks Doc...

I recognize that things *can* happen... I was just wondering if anything had changed that would give one reason to believe it will happen.

Cheers guys,
Scott


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## dragonblade71 (Sep 7, 2007)

"As always, it's a question of what you feel comfortable dealing with. If you feel you can keep yourself safe, and the risk is acceptable, then go for it. If not, there are loads of other species out there!"

As I live in Australia, I have no choice but to obtain an Aussie tarantula. Well at least that makes my choices easier when I go spider shopping!


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## Brettus (Sep 7, 2007)

> As I live in Australia, I have no choice but to obtain an Aussie tarantula


At least we don't have to put up with urticating hairs


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## Buckwheat (Sep 7, 2007)

I am not an expert but my dad has been keeping tarantulas for over 35 years and I would have to say that concerning tarantulas that are currently in the pet trade that there would be none that could produce any real effects other than for someone that might already have associated problems concerning stings or bites. Those people should either not be keeping anything that might cause a reaction or should not handle anything that can bring on that type of thing for them. I've been bitten more than a few times and have never had any type of reaction whatsoever. Just personal experience here.


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## DrAce (Sep 7, 2007)

Buckwheat said:


> I am not an expert but my dad has been keeping tarantulas for over 35 years and I would have to say that concerning tarantulas that are currently in the pet trade that there would be none that could produce any real effects other than for someone that might already have associated problems concerning stings or bites. Those people should either not be keeping anything that might cause a reaction or should not handle anything that can bring on that type of thing for them. I've been bitten more than a few times and have never had any type of reaction whatsoever. Just personal experience here.


*sigh*

I fear I really have had a point missed.  I'm going to step them out one by one:

There is no medical reason why you would be concerned about tarantula bites, at least rationally.

You should be aware, in the back of your head, that there is a whiff of a possibility that there may be a bad reaction to one, however.

The fact that there has been no recorded case, on the arachnoboards, of a severe allergic reaction to a bite is not reason to suspect it has not happened.

Not all anaphylaxis cases are recorded in journals.  They are not all written up where google can get them.  Not being able to find a case does not mean it can't happen.

There are proteins (call them peptides for all I care, there is probably a tertiary structure to them) in venom which may well be able to produce an allergic reaction.

There is some evidence to suggest that there is an allergic response to a bite - although it is not clear what the reaction was to.

An injection of venom, as far as I am aware, is not a highly purified jab of one protein, any more than urine is a single chemical in solution.

Someone with a sensitivity might not know it, and might get a bite and have a bad reaction.  It's unlikely, but possible.  Not something to worry about, but be aware of.


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## Venom (Sep 7, 2007)

Crotalus said:


> Dr Ace, zero cases of anaphylaxis in the litterature (and there are no shortage of bite cases from those spider species) might give us a hint that we can rule it out.
> So, unless someone provide documented cases I think its correct to say it doesnt cause it.
> 
> As you state yourself in your first reply here:
> ...


But you use this same approach to rule out the possibility of a tarantula bite ever causing a death, even with extenuating factors involved. Since I disagree with your position on that subject, I don't think I can agree with your logic here either. I think it's a case of exaggeration on both sides: you are saying it's flat out impossible, and DrAce is saying it's definitely possible. His logic is based on evidence of chemistry, and yours on observation of non-occurrence of anaphylaxis. 

I'm going to take the middle road and acknowledge the evidence of both, but the conclusion of neither: it is chemically possible for a reaction to occur, but all evidence suggests this to a very remote, unlikely possibility. It's not impossible, the chemistry shows it isn't impossible. However, not _knowing _of T-induced anaphylaxis doesn't mean it hasn't happened, or that it could not happen. But it shows it is unlikely to happen.

So in a way, I agree with both of you, but I'm not going to worry about an allergic reaction myself, and I'm not going to advise people to consider it among tarantula defense risks.

What I do advise people to consider is their own health. I don't feel that a tarantula has the potency to kill a healthy human of non-tender years, at least not to any probability that we need to consider. What I do consider possible, after reading many bite reports from a range of species, is that tarantula bites can be "medically significant,"--not life-threatening in and of themselves, but potentially so when combined with other, already serious medical conditions. Body-wide muscle cramping isn't too dangerous...but if you have muscular dystrophy, it's a different story. A tight chest and some breathing strain isn't going to kill you, but if you have cystic fibrosis or COPD, it's not so clear what may happen. Same goes with S.calceata-induced heart irregularities and heart disease patients, or severe swelling from poecs and diabetes patients, or neurological effects with MS patients. The tarantula bite taken alone is not fatal, but it might, in some species, aggravate or contribute to a pre-existent condition to the degree that one's life could conceivably be in danger. 

It's not a great leap of logic, and we have evidence both for the T bites causing certain effects ( bite reports, which ARE good sources of evidence ), and of certain diseases having effects along the same lines, or compromising systems in ways that leave a vulnerability to Tarantula bite effects. The only type of observed evidence we lack is what happens when diseases and T-bites interact, and with more and more people entering the hobby, it may not be long before we hear of this. Thus, I think *common sense* should compell us to advise novice hobbyists of the effects certain tarantulas can have, and the risks of interaction with similar diseases that they may pose.


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## DrAce (Sep 7, 2007)

I think that's a very reasonable position, Venom.

Incidentally, I'm again repeating that it's not likely, but possible.

On a different note, Venom, there is a lot of stuff for you to respond to in the watering hole.


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## Venom (Sep 7, 2007)

DrAce said:


> I think that's a very reasonable position, Venom.


Thank you  



DrAce said:


> Incidentally, I'm again repeating that it's not likely, but possible.


I know you think it's unlikely. It was just that, since you were having to defend the possibility, it _came out_ as if you were also defending the probability.



DrAce said:


> On a different note, Venom, there is a lot of stuff for you to respond to in the watering hole.


Yeah, I know. I'm out of energy and motivation however. There comes a time when it's not worth continuing the debate. If I kept this up indefinitely, I'd be doing nothing but research, and that's not the point of TWH debating. Don't worry, the subject will come up again before long.


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## Crotalus (Sep 7, 2007)

Venom said:


> But you use this same approach to rule out the possibility of a tarantula bite ever causing a death, even with extenuating factors involved. Since I disagree with your position on that subject, I don't think I can agree with your logic here either. I think it's a case of exaggeration on both sides: you are saying it's flat out impossible, and DrAce is saying it's definitely possible. His logic is based on evidence of chemistry, and yours on observation of non-occurrence of anaphylaxis.


As far as I can see no lifethreatening documented cases have been reported, only anecdotes (comatose cases that no one can provide details about etc)  and third hand information or reports made by layman and not a doctor. So yes I rule out there is a tarantula in the hobby that are capable of inflicting a lethal envenomation. And no im not saying its "flat out impossible" - im looking at the facts we have and how the venom works and make my opinion based on that. If there are a unknown species with a potent venom out there - who knows - but for all we know today its unlikely or atleast unheard of.

All respect to Dr Ace, but I prefer to go on Bryan G Frys knowledge about venom over Dr Ace on a hobby forum 



> So in a way, I agree with both of you, but I'm not going to worry about an allergic reaction myself, and I'm not going to advise people to consider it among tarantula defense risks.


Scorpion venom can produce a allergic reaction such as anaphylaxis (that is documented) but all the knowledgable people say that is so unlikely to get it its not worth mention as a possible risk. 
If thats the case with venom that are capable of inducing these reactions - then id say tarantula venom and allergic reactions are a nil risk.



> What I do advise people to consider is their own health. I don't feel that a tarantula has the potency to kill a healthy human of non-tender years, at least not to any probability that we need to consider. What I do consider possible, after reading many bite reports from a range of species, is that tarantula bites can be "medically significant,"--not life-threatening in and of themselves, but potentially so when combined with other, already serious medical conditions. Body-wide muscle cramping isn't too dangerous...but if you have muscular dystrophy, it's a different story. A tight chest and some breathing strain isn't going to kill you, but if you have cystic fibrosis or COPD, it's not so clear what may happen. Same goes with S.calceata-induced heart irregularities and heart disease patients, or severe swelling from poecs and diabetes patients, or neurological effects with MS patients. The tarantula bite taken alone is not fatal, but it might, in some species, aggravate or contribute to a pre-existent condition to the degree that one's life could conceivably be in danger.


Of course, if im suffering from a lifethreatening disaese - been bitten by anything venomous doesnt do any good to me. But you cannot say its the acctual venom in it self that are dangerous then. Its that persons general health that are already declining. Then again, I havent read any report of people with MS or any other disase getting bitten so that reasoning is purely hypothetical. I could say that tarantula venom might do them good since there are components in the venom that are useful in medicine. Thats just as wrong without anything backing it up.



> It's not a great leap of logic, and we have evidence both for the T bites causing certain effects ( bite reports, which ARE good sources of evidence ), and of certain diseases having effects along the same lines, or compromising systems in ways that leave a vulnerability to Tarantula bite effects. The only type of observed evidence we lack is what happens when diseases and T-bites interact, and with more and more people entering the hobby, it may not be long before we hear of this. Thus, I think *common sense* should compell us to advise novice hobbyists of the effects certain tarantulas can have, and the risks of interaction with similar diseases that they may pose.


Yes certain effects but far from life threatening. Keep that in mind. Bite reports written by "Joe, 21" with zero medicinal background is not so good in my opinion anyway. A increase in heartrate could easily be mistaken etc etc.
If im discouraging a novice to get poecs or stromatos its not because of the venom  - its because they are a handful to control for a beginner. 
if im discouraging a novice from getting Phoneutria its because they have a highly potent venom and are a nightmare to control for a beginner.


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## DrAce (Sep 8, 2007)

I think we're done here.  Both of us have articulated our positions in about as many ways as possible.

I think the conclusion from both of us is: forget about it.


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## DrAce (Sep 9, 2007)

*By the way*

By the way, for the first 10 years of the HIV pandemic, there was no evidence of heterosexual transmission.  It was thought to be impossible.

That ended well too.

Not all tarantula bites are reported in the medical literature, and certainly not all in English, where we'd get our hands on it.


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## Stan Schultz (Sep 9, 2007)

dragonblade71 said:


> I was reading a website which described possible symptoms that one could obtain from a tarantula bite and one of these was paralysis! The website does state that this would be temporary. ...


That website is fraught with all sorts of "mis-truths." It's another example of some one with more expertise in webpage development and much less in arachnoculture advertising their ignorance to the general public.

BTW, what is that wiggly thing in the upper left area supposed to be anyway?


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## Stylopidae (Sep 9, 2007)

Pikaia said:


> That website is fraught with all sorts of "mis-truths." It's another example of some one with more expertise in webpage development and much less in arachnoculture advertising their ignorance to the general public.
> 
> BTW, what is that wiggly thing in the upper left area supposed to be anyway?



I thought it was something NSFW at first, but then it turned out to be a rattlesnake's rattle.


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