Mark E. Reiber, M.D., F.A.C.S., F.A.A.O.A.

 

What is Allergy? You know it is sneezing, watery eyes,nasal congestion, and sinus infections, but do you understand it?. What causes allergy? Why do you have allergies? Why do you suffer greatly while someone else has mild symptoms?  What can you do to prevent allergies?

 

Studies show most patients believe they understand their allergies, but when quizzed, less than half knew the immune system was involved.  Few could explain the differences between types of allergy medications or even which type they were taking.

So what do you need to know without having to get a medical degree?

 

 “Antigen” is the smallest protein molecule causing allergic symptoms. When we say you are allergic to cats, it’s not the whole cat, just the Fel protein in saliva that gets on it's hair when licked. Protein antigens are found in pollens, molds and all allergic substances.  

 

 To be allergic, you must possess both an allergy gene for an antigen, and repetitive exposures to that antigen.

 

You get 23 pairs of chromosomes, one from each parent. Each is a long strand of DNA molecules composed of millions of genes instructing the cell how to grow, work and behave. Within immune cells are unique genes for each antigen to which you can be allergic. Rarely is anyone allergic to only one antigen. 

 

Genes are copied into RNA and then made into proteins.  Proteins are the workers performing the function and structure of the cell. In going from DNA to RNA to proteins are many steps for control and regulation.

 

If one parent has allergies, you have a 1 in 3 chance of developing allergies, and 1 in 2 if both parents are affected. If genes alone accounted for allergies, these numbers should be 50% and 100%, but there are many factors regulating gene expression. Patients with the same “allergy gene” can have different expressions and show mild, moderate or severe symptoms.  

 

Just having the allergy gene isn’t enough, there must be repetitive exposures. With first contact, your system detects, processes, and reacts without symptoms. Subsequent exposures cause increasingly greater responses with a full-blown reaction after the fifth exposure. Studies show your age may affect sensitization.  Exposing young children to cats or certain foods may be more likely to lead to allergy than exposures later in life.

 

Our immune system is a complex array of chemical reactions designed to protect us from the outside world. It recognizes foreign from self and eliminates or isolates invaders.

 

Common invaders include bacteria, viruses, chemical irritants, toxins, and allergens. The symptoms we experience are the consequences of our immune response. Fever, for example, results from the chemical, interleukin.  It raises the body’s temperature to improve immune system efficiency. The itchy, watery nose and sneezing you experience during an allergic attack is from histamine.

 

When functioning properly, our immune system eliminates foreign substances without harm; however errors can occur. In allergy, commonly encountered substances are recognized as harmful and the response is overly aggressive.

 

 An even greater problem can occur when the immune system mistakenly recognizes its own body as foreign, an “autoimmune” disease. Rheumatoid arthritis and lupus are common examples.   

 

Immune reactions are complex and intertwined like an elaborate interstate highway system or branching roads.   There can be many triggers initiating a reaction and different pathways taken. Viruses, bacteria, toxins, pollutants, and allergens are all triggers. Immune reactions for bacterial and viral infections take different paths, and for allergies, there are at least four unique types of reactions. 

 

Poison ivy is one type of allergic reaction known as delayed hypersensitivity. It takes several hours to develop and relatively minor.   A peanut allergy reaction on the other hand, is immediate and life threatening.  These are completely differernt types of allergic reactions with unique mechanisms. 

 

A powder keg, waiting to explode: 

Once the immune system has been primed by exposures, it is set to react more easily and severely, like an explosion erupting through a fireworks factory. Light one fuse and soon the whole place is exploding. When allergies are bothering you, it may seem like anything will trigger sneezing and dripping. When we treat nasal allergy, we concentrate on prevention and early intervention before things get out of hand.

 

            Allergies are a result of your genes and your exposures. The immune system is complex and functions as a defense system for the body. Allergy is an overly enthusiastic reaction to common proteins in the environment. There are many triggers, but once your immune system starts reacting it is more likely to do so again, and more severely. Prevention and early intervention is the best approach. (Next read How to Treat Allergies)

 

January, 2012