Can I Develop Allergies to Reptile or Amphibian? The Answer is actually yes!

I recently ran across an intriguing thread forwarded to me by “Polasian” who is a member of fauna that was intrigued by another fauna member who asked the question “Can I develop an allergy to my reptile, or amphibian.”

Given my chosen profession, Polasian asked me if I would be interested in posting some topic oriented herp healthcare discussions here on fauna to encourage public participation, where fauna members can freely ask questions regarding herp medicine, while engaging in the provision of feedback to their peers.

To start with a more professional introduction, my name Jason Olech, I am a 4th year veterinary student currently completing the end of my clinical year at University of Georgia’s Veterinary Teaching Hospital and I’m scheduled for graduation from St. George’s University as a 2010 DVM candidate in June. My interest in herps began long prior to the advent of my veterinary training and during my education I served as the First President and Program Director of the Veterinary Student Herpetological Society at St. George’s University. My responsibility’s entailed generating lectures, labs and clinical demonstrations for students interested in herp medicine & surgery.

I have since been asked by several fauna members to begin a topic guided Q & A thread for the purpose of answering questions relative to herp healthcare, which brings us to the current question that I found so intriguing; Can I Develop Allergies to Reptile & Amphibians? The Answer is actually yes!

After reading the thread I learned that select members had difficulty locating published literature on the topic, so I went on a search to see what I could dig up and these are a only few of the published articles and case reports that I found. I will furnish more publications later concerning this topic as I feel this is really important and certainly very interesting. It used to be thought that reptiles were ideal for people with allergic hypersensitivities because it was thought that they do not produce dander. The following publications below are veterinary sources and one case report concerning reptile/amphibian associated alergic hypersensitivities.

http://www.jiaci.org/issues/vol16issue03/11.pdf

http://aappolicy.aappublications.org/cgi/reprint/pediatrics;122/4/876.pdf

http://www.veterinarypartner.com/Content.plx?P=A&A=1276&S=4&SourceID=56

http://www.anapsid.org/reptileallergies.html

WOW

Jason, I honesty had no clue that reptiles can be an actual direct cause of this. Allergies are due to a defect in the immune system correct? If so, is it known what exactly it is about reptiles that causes this response in humans?

With cats (for ex) I think its such things as dander that forms after grooming which then causes all sorts of trouble, right? I think its because the body sees the dander as some sort of alien property, and assumes that it must be a disease or something? So what property is it in reptiles that causes allergies? If they have figured that out...are you aware of any type of immunotherapy treatments that can help "desensitize" people from reptile allergies?

OH and Jason, you can call me Nick .

It makes good sense. Reptiles produce a large quantity of particulate matter. They shed skin, feces, urine and saliva and various other organisms, some of which are known to cause disease in humans and all of these materials contain immune stimulating particles called antigens. Antigens are typically composed of polysaccharides (long chains of sugar molecules), or proteins (long chains of Amino Acids molecules) and typically measure more than 1000 daltons in size, which is the scale used to measure proteins.

Thank you Nick, I like first names better as well Allergies are not really a defect in the immune system, because the immune system is doing exactly what its supposed to. The problem is that your immune system becomes hypersensitive (meaning too sensitive) to the chemicals stimulating it and the reaction is so great that inflammation begins damaging local tissues. Once damaged, more inflammation occurs resulting in the symptoms we commonly observe during allergic reactions.

In both reptiles and amphibians allergic reactions are most likely due to exposure to shed skin particles, bacteral laden excrement and saliva. The component of these materials that would be capable of stimulating an immune reaction would be the protein and polysaccharide components of the cellular constituents measuring larger than 1000 daltons. Exactly which specifically, I do not know. I would be interested to know this myself and will look into it.

As for allergy therapy, I have not yet heard of this being done, though that doesn't mean someone isn't working on it especially when more and more publications concerning reactions in humans are being published. Though allergy therapy may be a step towards a potential solution, such therapy does not work for everyone. Ultimately exclusion is the fastest means to the resolution of clincal signs given that you need to remove the stimulus eliciting the immune reaction.

Olexian Pro said:

Antigens are typically composed of polysaccharides (long chains of sugar molecules), or proteins (long chains of Amino Acids molecules) and typically measure more than 1000 daltons in size, which is the scale used to measure proteins.

Click to expand...

OH OK, so these allergies are not caused by any specific reptile property...but instead they are caused by the generic antigens which are shared by many species of animal? So its the protein & sugar molecules WITHIN the reptiles properties (scales, saliva, etc...) that are common across the full spectrum of animals? For ex, the protein that might be found in cat dander is the same protein that might be found in dried reptile scales? So ultimately its said protein that is the source of the allergies?

That seems to be what I gather from the articles, as well as from what you stated here. However, I'm confused. If the antigens are shared by all animal "properties," then why are some people only allergic to cats but not dogs, and vise versa?

Also, I looked up pet immunotherapy treatments but they seem to have one treatment process for cat allergies and another treatment protocol for dog allergies. Yet I cant find any immunotherapy treatments dealing specifically with reptiles. So if these antigens are the source of all the trouble, and if they are consistent from animal to animal, then why are there different immunotherapy treatments for different animal allergies?

Here, the following is an article dealing specifically with "Cat immunotherapy treatments."

Cat Allergy Treatment Through Immunotherapy
Immunotherapy is an ideal cat allergy treatment for the allergic owner who can't bear to part with her cats, no matter how much her pet's dander irritates her.

Symptoms of Allergies to Cats

The symptoms of allergies to cats are similar to those of most allergies. Sufferers will experience sneezing, runny nose, sinus headache and teary eyes. However, pet owners with cat allergies will also have skin rashes or hives as a result of contact. More serious cases of allergies affect the lungs, causing wheezing or shortness of breath. If you feel like you get upper respiratory infections more often than others, it may be a result of an allergy to your cat.

Though your doctor may assume that you have cat allergies if you have dermatitis, eye infections or asthma, and you own a cat, this may not be the case. Only an allergy test can tell for sure.

The severity of symptoms can determine what course of treatment is available to the owner. Severe symptoms as a result of a cat may leave no other choice than to adopt out your cat. However, humans with mild cat allergies may undergo immunotherapy treatment.

The Source of the Allergy

The allergen element of cat dander is a protein from the cat's sebaceous glands. The protein dries on the skin and is shed wherever the cat goes, and remains for years where the cat had been. Neutered male cats shed the least, while intact male cats shed the most, as the production of the protein is based on hormone levels.

How Immunotherapy Works

Immunotherapy treatment desensitizes the patient to the cause of their allergies. The treatment has no benefit in fighting allergic reactions to food allergies, but has proved effective in seasonal and pet allergies.

The treatment uses a series of injections to make the patient less susceptible to the symptoms of cat allergy by treating the cause. Your doctor will give you one or two feline allergy shots a week for six months, inserted under the skin. Over time, the injections, which contain extracts of the allergen, will become larger, gradually increasing the tolerance to the source of the allergen. These allergen vaccines make up the build up portion of immunotherapy.

After the desired dosage has been reached, your doctor will begin the maintenance phase. At this point, most of your feline allergy symptoms should have been alleviated. Consequently, your shot frequency will decrease to once a month, for a few years.

The treatment will continue until the patient no longer experiences allergic reactions when around the source. This is a fantastic option for pet owners with mild cases of cat allergy, as the treatment has not proved effective for severe cases.

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http://www.vetinfo.com/cat-allergy-treatment-immunotherapy.html

Olexian Pro said:

Allergies are not really a defect in the immune system, because the immune system is doing exactly what its supposed to. The problem is that your immune system becomes hypersensitive (meaning too sensitive) to the chemicals stimulating it and the reaction is so great that inflammation begins damaging local tissues. Once damaged, more inflammation occurs resulting in the symptoms we commonly observe during allergic reactions.

Click to expand...

Ahhhhhhhh...ok, now I get it.

Olexian Pro said:

As for allergy therapy, I have not yet heard of this being done, though that doesn't mean someone isn't working on it especially when more and more publications concerning reactions in humans are being published. Though allergy therapy may be a step towards a potential solution, such therapy does not work for everyone. Ultimately exclusion is the fastest means to the resolution of clincal signs given that you need to remove the stimulus eliciting the immune reaction.

Click to expand...

This actually brings up a good point. Lets say the immunotherapy treatments are fruitless. Prior to getting rid of ones animals, are there steps that can be taken to try and lessen the adverse effects of the antigens?

I'm sure I don't have to tell you but herping is an addiction . It hurts peoples wallets, social life, sometimes even sanity . So if someone who has been diagnosed as having herp allergies, was able to take some precautions to minimize the negative effects to their health...I'm sure they will be able to live with that. I know I would . Hell, I cant even put down a cigarette and I know that's bad for me.

By "precautions" I mean...using a certain type of hand disinfectant, or wearing some sort of mouth cover/mask, etc... while dealing with their animals.

Before we look at the management allergies I think it is critical to first understand the properties of antigens and the function of the immune system in a bit more depth. As I said before, virtually all living tissues contain antigens; even human tissues are antigenic if introduced into another individuals body.

The term antigen is relative to the environment (or body) in which they are produced. meaning that tissues in my body contain antigens, no doubt about it, but those antigens are recognized in my own body as self-antigens because I made them and they have chemical sequences that are unique to me and me only. As a result these antigens are left alone by my immune system, because they are recognized as something my body made and thus, they belong.

If I were to introduce tissues from my body into your body (like a skin graft for example), your body would rapidly recognize that those tissues were not produced by you and your immune system would wake up in an attempt to destroy my tissues, which your body recognizes as foreign because they do not match the antigenic chemical sequences that your body is coded to recognize.

Your body has to have some way to recognize self-material from non-self material, so how exactly does your body do this?

First lets recap.

Virtually all living tissues contain antigens, which are molecules composed of numerous proteins and polysaccharides. Proteins are composed of long chains of amino acid molecules and polysaccharides are composed of long chains of simple sugar molecules. There are many different types of amino acids and many types of simple sugars.

As a vast over simplification, these building blocks can arrange themselves in any order, or sequence they want and when they do this the resulting product is that of proteins and polysaccharides. It is possible to have two proteins or sugars who's sequences are identical, though this is rare.

In the case of protein, it is possible to have two functionally similar proteins with two significantly different amino acid sequences and this is where the picture becomes scientifically hairy and difficult to understand.

Though on the same token, it is the reason that your body recognizes your own protein-X (with the make believe sequence-GATCC) as a self-manufactured molecule and not as a foreign particle. Whereas my protein-X (with the make believe sequence-TATGC) would be recognized by your body as a foreign particle. One of the many reasons this occurs is because my protein sequence (TATGC) does not match your Protein Sequence (GATCC). Your body is primed to recognize these differences early in embryonic development, which is a task carried out by numerous cell types, among which include embyronic dendritic cells.

As I said prior, this is a massive oversimplification for the sake of understanding. The immune system is very complex and many more aspects of cellular function are affected by differences in protein sequence and the presence of polysaccharides. In addition, many other factors contribute to what is recognized as an antigen and what is not, and in truth we do not yet fully understand the full dynamics of the host immune system, which is a major field of research currently underway.

Now back to your question. Are the chemicals that we classify as the antigens in cat dander, dog hair and reptile skin the same? The answer is no, they are not. They belong to the same chemical classes (such as proteins and complex sugars) yes, but the chemicals themselves are quite different in size, shape and sequence. The reason all of these are capable of causing immune reactions is because they are composed of large molecules that are unique to each individual and are recognized by the body as such. This enables our immune system to distinguish self-antigens from non-self antigens. If identified as self, they body will normally leave them alone. If identified as non-self, the body will label them for removal with an antibody and the immune system will destroy it. At times this reaction can go AWAL if you will, resulting in autoimmune disease.

In theory, autoimmune disease occurs as a result of chronic inflammation wherein the immune system causes so damage to self-tissues that new self-antigens are consequently exposed. Despite being recognized as self-antigens, these newly exposed antigens are novel enough to the immune system that they are recognized as non-self antigens and a perpetual cycle of inflammatory tissue destruction occurs. When this happens, the immune system begins attacking normal healthy self-tissues giving rise to autoimmune mediated tissue destruction where the body begins killing itself, as if it was its own foreign invader.

Ideally it isn't fair to say that immunotherapy (allergy shots) is ineffective, or a waste of ones time. In contrast this is not true. Immunotheraputics have been used with great successful in a number of individuals, but given our limited understanding of the immune system it is not without some margin of error, or failure of success. In more severe cases, where immunotherapy is unsuccessful, immunosupressive therapy may be of use and has been used for the short term treatment of severe allergic reactions to vaccines, as well as for long term therapy applied to individuals with autoimmune disease.

As of right now these are the major therapoutic modalities available In addition to the practice of dietary modification, feeding trials, exclusion diets, etc.

In most cases, it is easier to remove the inciting cause of an allergic reaction than it is to treat the symptoms once an allergic reaction has developed.

As for immune hypersensitivity, one of the current treatment modalities would by that of immunotherapy where the goal of therapy is desensitization. To achieve this, the patient is subjected to intradermal skin testing where bleb injections are administered beneith the skin containing antigens that have been isolated from a variety of substances, some of which may be known to cause clinical signs of hypersensitivity in that individual. Positive and negative controls are also applied concurrently. Once administered, a given period of time is allowed to elapse and the bleps that form on the surface of the skin are then measured to see if swelling has occurred as a result of allergic inflammation.

Once the eliciting substances have been identified, vaccines are prepared for subcutaneous injection containing the same antigens which have been diluted so much, that the concentration present is not high enough to elicit a strong/dangerous immune reaction. These vaccines are then administered over a given period of time and the concentration within the vaccine is gradually increased as time progresses. Doing so allows the hosts immune system time to develop a tolerance to the antigens. As the concentration of the antigen contained increases, so does the bodies tolerance to that antigen, until the individual becomes so tolerant that they no longer react when exposed to the antigen that previously caused an allergic reaction.

Many vaccines also can and sometimes do cause reactions in people, as well as animals. So how do we vaccinate someone who reacts to the vaccine they are given? For these individuals we often employ preventative therapy with short acting anti-histamines, steroids and immune modulators. These must be given to the patient before exposure to a given allergy stimulus to preventative the onset of a reaction. These reactions can be life threatening and should be considered a medical emergency.

In veterinary medicine, immune modulators such a azathioprine, cyclosporins and other drugs such as corticosteroids have been used to control SEVERE allergic reactions. These agents however are reserved only for severe cases of immune hypersensitivity and autoimmune disease and should only be used by a medical doctor or a veterinarian.

The mainstay of allergy therapy ultimately, is the exclusion of the inciting stimulus +/- immunotherapy if desired by the patient. This can be very challenging for the patient as well as difficult to achieve. In veterinary medicine we often use feeding trials, or dietary exclusion to identify food allergens, though we do have serology and intradermal testing available to us.

If we are faced with a patient who has a history of vaccine reactions, we will often treat that patient pre-emptively using short acting drugs to prevent an immediate reaction. If the stimulus is something continuous that cannot be removed such as the case with autoimmune disease, we then turn to the use of immune modulators to quiet the affects of the immune system.

I have return to work for now, but later I will post more about allergies in general and followed by an explanation of how it applies to herps.

With respect to immune hypersensitivities, there are between four to five different types of hypersensitivity reactions. When we consider reptiles or amphibians as a cause of allergic reactions, we are concerning ourselves with type I immune hypersensitivity reactions specifically, which happen to be mediated by the immune protein IgE. The antibody IgE is one of the immune system modulators responsible for allergic reactions and is active during parasite infestations as well. IgE binds to the antigens present on the surface of biologically active foreign material. The antigen-antibody complex then behaves like a switch capable of activating eosinophils, mast cells, basophils and other immune constituents that trigger the immune response, giving rise to the gross appearance of allergies.

When determining the cause of allergies, intradermal testing and serology may be employed depending on the antigen/antigens of interest. Allergy therapy is tailored to the needs of the individual based on the severity and types of symptoms observed and may include the use of dietary modification by exclusion, feeding trials, environmental modification, Immunotherapy, or possibly the use of drugs such as antihistamines, steroids and immune modulators in severe cases.