Any moment now, the pollen will be exploding from trees and grass, and the spring allergy season will be tormenting many of us.
So we thought it would be nice to review what this is all about, and what you can do.
What is an Allergy?
The word allergy was made up by a pediatrician (!) in 1906. He decided to create a word that indicated that a certain type of energy was being devoted to a bit of work. Allergy was a good invented word, since the al comes from the Greek word allos meaning other, and ergy comes from the word energy which ultimately means work.
So an allergy is a bit of work the body does against something outside the body. The work is done by one system of the body, the powerful immune system. The work the immune system does is to create inflammation, a very special and unique type of inflammation called the allergic reaction.
Each person’s experience of allergy is completely defined by the following properties common to all allergies:
- There is some item that the immune system responds to, almost always a protein that is part of a substance.
- If you contact that item, your immune system activates a response that creates inflammation at the site of the reaction.
- The reaction creates inflammation, which in the case of allergy is a watery, red, itchy, and swelling sort of inflammation.
- Symptoms are always the result of where that inflammation occurs
- Eyes: watery, red, itchy, swollen eyes, with crusty and goopy mucus
- Nose: water, red, itchy, nose with crusty and goopy mucus and sneezing
- Throat: sore throat with phlegm
- Voice Box: hoarseness or barking cough, coughing up mucus
- Lungs: cough, wheeze, shortness of breath, coughing up mucus
- Skin: itchy skin with hives or eczema
Since all of allergy is about inflammation, it makes sense to understand it a bit better.
Inflammation is a great scourge, but necessary for life. When it helps we call it our immune defense system, when it causes needless trouble it is called inflammation. But either way, inflammation is the action of the immune system to kill germs or harmful cells. It is a set of actions that destroy cells. If the cells are bad, we like the destruction as long as only the bad cells are affected. If the destruction is unnecessary or excessive, we call it inflammation.
The destruction can occur in two main ways: by chemical attack, or by attack by actual cells of the immune system.
Chemical attacks can vary by the nature of the inflammation. For allergy, the chemicals are mainly histamine and leukotrienes.
Allergic inflammation is peculiar and unique because its roots derive from a very surprising source- this inflammatory mechanism was originally designed to kill worms.
That’s right, all classic allergies are actions taken by the department of the immune system entirely devoted to responding to infections by worms. The histamine and leukotriene chemicals released with allergy are also used when the immune system finds a worm in the body and tries to kill it.
It goes beyond that. The immune system makes 5 different types of antibody, one of which, and only one, the E type, kills worms. That also turns out to be the only type of antibody we make that determines whether you have an allergy. That is so because to be allergic to something means you make an E-category of antibody to that one molecule. If you are allergic to cats, it can only be because you make an E type of antibody to a very specific protein in the saliva of all cats.
If you have an E category antibody to some molecule, then when the molecule appears, that E type of antibody makes certain cells explode a big load of histamine and leukotrienes.
These chemicals make blood vessels in the area leaky, and of those blood vessels are in wet tissues open to air, like the eyes, nose, throat, voice box, and lungs, you will get swelling in those sites, make lots of mucus, and get itchy. In the skin, that swelling stays contained, so there is no mucus, but plenty of swelling and itch (aka hives).
But allergic inflammation also can involve cells that go into attack mode. Say a pollen grain lands in your nose, and your are allergic to that pollen. All those inflammatory chemicals appear there, but so do a wad of attack cells, making things only worse. This is the way an allergic reaction can last weeks. And in the skin, it is the cellular attack that creates eczema.
Allergic inflammation, for all its miseries has two rather remarkable properties other causes of inflammation do not:
- If you can avoid the thing you are allergic to, no inflammation happens.
- For most allergic inflammation, once it goes away, it leaves far less damage behind (usually none) than others.
So, if you are allergic to peanuts, don’t eat peanuts, and no inflammation will happen by that allergy.
And, if you have pollen allergy and have a swollen runny nose and eyes for 2 months this spring, once that ends your eyes and nose will be fine.
This is a far cry from more usual causes of inflammation like arthritis, where no one can control if you get the inflammation, and it often leaves the tissue quite impaired and damaged.
Given the very specific qualities of inflammation in allergy, there are some very specific treatments that can help:
- Avoid the thing you are allergic to. This works best for foods, not so well for pollen.
- Anti allergy chemicals. The key chemicals of allergic inflammation are histamine and leukotrienes. Anti-histamines (Benadryl, Claritin, Zyrtec, Allergra) and anti-leukotrienes (Singulair), work all the same way, they block the ability of these chemicals to create a reaction. When they work well, all allergy symptoms in all parts of the body feel better. For the eyes and nose there are antihistamine drugs to reduce allergic reactions in the eyes and nose.
- Steroids. Steroids kill the cells that make allergic inflammation happen. If you sniff nasal steroid or inhale steroid, you can drastically reduce allergic inflammation in the nose or lung, respectively. Oral steroids are not safe to take all the time, so they are not used for allergies that are commonly recurring, like hay fever, except in exceptional and rare circumstances.
- Allergy shots. Allergy shots create a G-type of antibody to what you are allergic too, blocking the ability of that item to reach the E-type, and voila, no allergy. They do not always work, but if they do, allergies can be dramatically reduced.
- We are in the full swing of spring pollen allergy season.
- Allergies are a very specific type of inflammation that our immune systems create, for no very good reason.
- There are ways to reduce the power of allergic reactions.
We hope this year’s allergies are mild and if not, that we can help you find a path for relief!!
To your health,
Dr. Arthur Lavin