'This definitely does NOT apply to all arachnids. As far as I know, many (if not all) true spiders do have protein chains in their venom. Probably the same with scorps. Theraphosid spiders (tarantulas) are lower on the evolutionary ladder than most other arachnids and their venom is likewise less evolved.
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-Ethan'

Quote: By Venom

'Quote:
Originally Posted by etown_411 View Post
There are different types of reactions a person can have to foreign substances, one of which is an allergic reaction. There are also different types of allergic reactions, one of which ia an anaphylactic allergic reaction. This has something to do with the contaminant bonding with histamine, not sure of the specific action. Anaphylactic reactions are the type that typically causes death from swelling and blockage of airways. People who are deathly allergic to bees suffer this type of reaction.
Quote:
The prevailing opinion is that the peptide chains in tarantula venom are physically too small to bind with the histamine and therefore cannot cause a dangerous anaphylactic reaction. Again, this is the prevailing opinion, it's not a proven fact. There are other sorts of sensitivities that a person can have to venom that could still be dangerous.
I FULLY agree. Individual health factors need to be considered. If the person has a pre-condition that makes them more vulnerable to the action of the usually non-life-threatening venom ( say, they have cystic fibrosis or MS ), this could result in a COMBINATION of threats which could elevate the T-bite to a "straw that broke the camel's back" situation.

Quote:
There's also the possibility of secondary infection, tetanus (they carry dirt around with those fangs) and general high levels of sensitivity to certain venoms. Just because one (supposedly) cannot have a violent anaphylactic allergic reaction to a bite doesn't necessarily mean that bite is harmless.
This really depends...captive-bred, captive-owned tarantulas are not generally kept on "dirt," but on potting soil ( acidic/ anti-microbial ), potting soil, vermiculite, coir, etc. The probability of these containing tetanus-causing bacteria is extremely, extremely low ( especially for the peatmoss, which when moist, is acidic and a mild anti-microbial ). Tarantula venom is also anti-microbial. But certainly, as you say, the no-allergy clause does not mean we take these bites lightly....EVER.

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For example, the only recorded death from a centipede bite was from a young girl who was bitten in the neck. She apparently died from suffocation when her neck swelled dramatically and blocked her airway. The venom was responsible for her death but did not directly kill her.
I was aware of this death ( from an S.subspinipes ), but had not heard the specific cause. Are you sure it was suffocation, and not shock due to overwhelming pain? She was only 7. My searching hasn't yielded any reports about it having been anaphylaxis that killed her.

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I believe it's not outside the realm of possibility that something like this could happen if say, a P murinus or S calceatum or whatever bit a child on the face or neck.
Hmmm, yeah. I can't disagree. These species, as with Poecilotheria and other Selenocosmiinae, cause a severe amount of swelling, but that is not the result of a histaminic immune response, as far as I am aware. Still, a severely swelling T-bite on the neck, would be serious without any immune involvement.


Not comforting words, I know but those are my thoughts from the "better safe than sorry" side of the fence.[/QUOTE]
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"all variety of created objects which represent order and life in the universe could happen only by the willful reasoning of its original Creator, Whom I call the Lord God." --Sir Isaac Newton.
Quote:
Originally Posted by codykrr View Post
I was specifically talking about the constitution...not the retarded laws they have made...'

'I at one point agreed that T venom was not able to cause allergic reactions, now I disagree.

Clinical Toxicology
Publication details, including instructions for authors and subscription information:
www.informaworld.com/smpp/tit...ent=t713597279
Abstracts
Online Publication Date: 26 December 2004
123. Envenomation from a ‘‘Fringed Ornamental’’ Tarantula (Poecilotheria ornata)
Dougherty TJ, Greene TF, Burkey WR, Rodi A. Cape Coral Hospital, Cape Coral FL; Lee Memorial Hospital, Fort
Myers FL.
Background: The ‘‘Fringed Ornamental’’ (Poecilotheria ornata) is an ‘Old World’ tarantula native to Sri Lanka. Lay publications claim its venom to be the most potent of all tarantulas with unsubstantiated reports of coma and paralysis.
The true risk of envenomation, however, is not reported in the medical literature. We report a case of envenomation by this exotic spider. Case Report: A 20-yr-old female was bitten on her right third finger by her pet tarantula. Thirty minutes later she presented to the emergency department, complaining of swelling of her finger, pain radiating up to her axilla, and chest tightness. The patient denied SOB, N/V paresthesias, itching, numbness, or difficulty swallowing. Her vital signs were normal. Her physical exam revealed a puncture wound at the tip of her third right finger, tenderness, and swelling of the pulp surface. No arm swelling, but right axillary tenderness, was noted. Her exam was otherwise unremarkable. Initial treatment included ketorolac 30 mg IV, methyprednisolone 125 mg IV, lorazepam 1 mg. The patient was transferred to In-Pt Toxicology service and was observed overnight. Lab:CBC, CMP and Sed Rate were nl., as were PT/PTT, fibrinogen, and D-dimer. The patient was released on antibiotics, antihistamines, and prednisone. On day 6, she returned, complaining of arthralgias with movement of her third MCP joint, wrist, and elbow with tender axillary lymphadenopathy. Immunological studies were ordered: IgA, IgM were nl, IgG was slightly decreased. IgE was elevated 141 KU/L (nl<114). She was given a medrol dose pack. One week later her symptoms had abated. Conclusions: We report of an envenomation from Poecilotheria ornata with resultant pain and arthralgias successfully treated with steroids and antihistamines. Elevation in serum IgE suggests an allergic response to the venom.

Rook's Textbook of Dermatology (Seventh Edition)
Published Online: 4 Feb 2008
Editor(s): Tony Burns, Stephen Breathnach, Neil Cox, Christopher Griffiths
Print ISBN: 9780632064298 Online ISBN: 9780470750520
Copyright © 1968, 1972, 1979, 1986, 1992, 1998, 2004 by Blackwell Science Ltd
Diseases Caused by Arthropods and other Noxious Animals
Chapter Author: D. A. Burns

www.healthcentral.com/ency/408/002855.html

arjournals.annualreviews.org/....010184.000403

www.sciencedirect.com/science...ba5810ce96393e

www.emedicine.com/emerg/TOPIC550.HTM

www.nlm.nih.gov/medlineplus/e...cle/002855.htm

so more research is needed of course.
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peace

Rev
Fides Non Timet '

Wow very interesting, thanks Taki

Quote from 'gumby'

'So over the past week I've been pondering how much of what we say on the boards is pure knowledge and how much is past down hearsay. I asked my girlfriend who has two BS degrees, in biology and chemistry, to take a look at this board and tell me what she though about this thread. She did some reading and sent me back this response:

Medical Microbiology 5th edition (Murray, Rosenthal, Pfaller) Elsevier

IMNHO:
In spider venom, there are small "proteins" which are called peptides. These peptides bind several receptors on the surface of your cells. This binding signals, among other things, pain. In response to this signal, and the bite itself, your immune system will respond. Worse, however, is that the venom can cause cells to burst, which elicits a huge immune response. When cells burst, they release toxins, which cause nearby cells to also be damaged. This collective damage is what the immune system is actually responding to. One way your immune system fights things that are not bacteria or viruses is by releasing histamine. Histamine is what gives you seasonal allergies. It signals more immune cells to the site, which causes swelling. This is not necessarily how the immune responds to the venom, but rather to the damaged caused by your cells bursting.

In tarantula venom there aren't the peptides that cause the cells to burst, but there are other peptides. But tarantula venom *can* cause an allergic reaction still, just like common food or plant allergies. Symptoms of this would include itching or mild swelling, but since it will be at the site of the bite, it won't be life threatening.
I also read that in some species of tarantula, in addition to these peptides there are "proteases", or enzymes that "chew up" protein. This can include structural proteins, including cartilage, which would cause bruising and tenderness.

More interestingly, there are groups of chemists using the structures common to different kinds of venom to cause the opposite effects: pain killers. They are using the idea of venom, that it binds cell receptors, but then are changing the peptide so that it will not cause the response, pain. But by blocking the receptor without triggering its response, other things that may bind would not be "felt" because the mock-venom would be shielding the receptor.

In short, an immunologist would call both of these responses "allergic", however to the average person on the street, the cell bursting response would be much more identifiable as an allergic reaction.

imb.uq.edu.au/download/large/...erapeutics.pdf
www.smbs.buffalo.edu/CENTERS/...pdf/NAture.pdf
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One more reason roaches are awesome
My Reviews www.arachnoboards.com/ab/showthread.php?t=75596 '