By Dr. Christine Fusillo, MD in November, 2010
Allergies... We certainly hear that word a lot today. It is estimated that 50 million Americans suffer with some form of allergy, placing it on the top of the list of medical ailments. So what actually causes allergies and why do allergies appear to be on the rise?
Allergies are directly connected to the state of our immune system. Our immune system is our defense system. When working right, the immune system will protect us from disease. It can muster up all kinds of cells and protective substances to kill the invading organism.
The immune system is composed of many things, some are cells that function to protect us and some are compounds our bodies make. T cells are an important part of our immune system. When a person’s T cells are attacked and depleted, it can result in one of the most devastating medical threats of our lifetime: AIDS. So T cells are an important line of defense. One of the compounds your body makes is a family of substances called antibodies. When we take our children (or ourselves) to get a vaccination, our bodies also make antibodies against the agent in the vaccine (be that the flu, measles, mumps, or polio). These antibodies will then circulate in our bloodstream to fight the invading organism.
Believe it or not, an allergy is the result of the over−production of an antibody. I know this might sound confusing. If antibodies are good for us, how is it that an over−production of antibodies could cause an allergy? Well, it has to do with where this particular allergic antibody lives. The name of this antibody is Antibody E. It lives on the outside of cells in our body called mast cells. We can all make this antibody but an allergic person can make hundreds or thousand more than a non−allergic person. This is what differentiates an allergic from a non−allergic person.
Let’s go back to the Antibody E and the mast cell. Consider that a person is allergic to dust and makes too much Antibody E against dust. When their body comes in contact with dust, the Antibody E will bind to the dust.
When this attachment happens, it causes the mast cell to open up and release the chemicals that are inside of it. The most commonly known chemical is histamine but there are many other chemicals that are released. Histamine can cause a variety of symptoms based on where it is released, for example, itchy eyes, sneezing, itchy throat, cough, hives, etc. If histamine is released in the stomach or intestines (as in the case of a food allergy), then the results can be vomiting, diarrhea, or stomach pain.
Therefore, if a person makes too much Antibody E, they will have problems with allergies. It appears that we are becoming a population with an increased risk of developing allergies. Why this is happening is the subject of intense study. One of the many theories being suggested is the hygiene hypothesis. We are becoming “too clean.” Our homes are cleaner (we are no longer living with dirt floors or have barns), we are receiving more vaccinations, and we are taking more antibiotics. As a result, we are making it easier on our immune system and, in the process, compromising it. As it is becoming weaker, we are favoring the production of Antibody E. This over−production of Antibody E explains why we are seeing a rise in allergic disorders including nasal allergies, asthma, food allergies, and eczema. Although no one is suggesting that you stop vaccinating your children or that you move to a farm, it is important to consider this hygiene hypothesis when taking into account all possible reasons for the rise in allergies.
The rise we are seeing in the number of allergies being reported is just one manifestation of a change in our immune system. We are also seeing a rise in the rate of gastrointestinal problems, like celiac disease (gluten sensitivity), Crohn’s Disease and Ulcerative Colitis, IBS (irritable bowel syndrome), and other immune disorders (rheumatoid arthritis, thyroid disease). The research continues as we try to determine why this trend is occurring and what we can do to reverse it.
In Memory of Dr. Fusillo
We're thankful for Dr. Fusillo, her brilliance and passion in her work. Her work continues to inspire and educate us and many others.