Some Allergy Basics
As we glory in the return of a warm sun, of the return of new life as plants start to grow and green, we also start to think about allergies.
Of course, allergies to many things occur all year round, including food allergies, allergies to pets, allergies to dust and mold.
But there is one sort of allergy that is defined by its seasonality- allergy to pollen. Like dust and mold allergies, pollen allergies are responses to substances in the air. But these substances only appear during cycles of plant reproduction, which largely go dormant during the winter, but burst onto the scene every spring.
This week we can all see trees flowering, and so the great burst of spring pollen allergy is upon us. Before talking specifically about this, let's do a quick reminder of what all allergies are about.
What is an Allergy?
All allergies are reactions to some substance from outside the body, and they are reactions that appear to serve no helpful purpose. All allergic reactions are also united in being in the category of inflammation.
If all allergic reactions are types of inflammation, what is inflammation? Inflammation is a series of events that living organisms use to fight off other living organisms. It turns out all sorts of inflammation involve some combination of five events: redness, swelling, warmth, pain, and loss of function. A great example of a common inflammation is a mosquito bite. The mosquito saliva causes four aspects of inflammation to occur- redness, warmth, swelling, and pain (or itch).
But there are lots and lots of inflammations, including all infections, many types of injury, auto-immune events, nearly every medical situation finds inflammation present.
So what makes any inflammation an allergic sort of inflammation? The answer to that requires us to mention that there are two sorts of allergies- classic and alternative. Alternative allergies are reactions that are not yet fully described, as when someone states they have an allergy to gluten.
Our discussion will focus on classical allergy.
What is Classical Allergy?
So classical allergy is a very specific type of inflammation that only happens when some item outside the body connects to a special type of antibody and once connected that paired unit activates the allergic reaction.
The special type of antibody is the E-class of antibody. There turns out to be 5 such classes. The M and G classes are involved in fighting off infections. An A class provides a barrier to infections in all the linings of the body. There is actually a class, the D class that no one knows what it does. And then there is the E class, which does two things- it helps clear out infections from worms, and it causes all classical allergies.
The way classical allergies work, all such allergies including to foods, pollen, dust, pets, molds, is that the item you are allergic to is able to connect to an E-class of antibody. Once that link occurs, the antibody triggers a release of compounds such as histamine that create the allergic inflammation, the allergic reaction.
Four things are common to all classic allergies:
1. One is that there is a very specific E-class antibody that will only accept attachment to one and only type of molecule.
2. The second is that a key property of the E-class antibodies, is that they all have their stem planted in a special cell called the mast cell.
3. The third universal of all classic allergies is that all mast cells are packed with compounds that cause blood vessels to get leaky and draw in inflammatory cells. If those contents are released for any reason, the area around these cells gets red, swollen, very itchy.
4. The sequence in every classical allergic reaction, then, is always the same:
Spring Allergies- How Best to Manage and Treat
When it comes to the hay fever appearing now, in the spring, we are talking about a classic allergy to pollen.
Pollen is in the air, so the allergic reactions to it are seen where air hits the body- the nose, the eyes, the throat, and the lungs.
In every part of the body that pollen contacts and causes a reaction, the same inflammatory reaction described above happens. The only difference is in the impact of inflammation in different parts of the body.
What does that mean? Well, for every part of the body affected, another symptom occurs:
The way classical allergies work, all such allergies including to foods, pollen, dust, pets, molds, is that the item you are allergic to is able to connect to an E-class of antibody. Once that link occurs, the antibody triggers a release of compounds such as histamine that create the allergic inflammation, the allergic reaction.
Four things are common to all classic allergies:
1. One is that there is a very specific E-class antibody that will only accept attachment to one and only type of molecule.
2. The second is that a key property of the E-class antibodies, is that they all have their stem planted in a special cell called the mast cell.
3. The third universal of all classic allergies is that all mast cells are packed with compounds that cause blood vessels to get leaky and draw in inflammatory cells. If those contents are released for any reason, the area around these cells gets red, swollen, very itchy.
4. The sequence in every classical allergic reaction, then, is always the same:
- Item that you are allergic to connects with the antibody that will only connect with that item
- Once the allergic material and antibody link, the stem of the antibody activates release of inflammatory chemicals that create the allergic reaction
Spring Allergies- How Best to Manage and Treat
When it comes to the hay fever appearing now, in the spring, we are talking about a classic allergy to pollen.
Pollen is in the air, so the allergic reactions to it are seen where air hits the body- the nose, the eyes, the throat, and the lungs.
In every part of the body that pollen contacts and causes a reaction, the same inflammatory reaction described above happens. The only difference is in the impact of inflammation in different parts of the body.
What does that mean? Well, for every part of the body affected, another symptom occurs:
- In the eyes- red, itchy, watery and/or mucusy eyes, with or without swelling
- In the nose- runny nose, congestion, itchy nose, sometimes redness and swelling
- In the throat- sore throat, mucus in the throat
- In the lung- cough and/or wheeze, mucusy cough
So what to do? There are 4 key strategies to manage springtime (and other) allergies:
- Avoid contact- this is hard, pollen is in the air, so avoidance is hard, but some homes have air filtration systems that might help do this at least a bit.
- Antihistamines- these common drugs are incredibly safe, and incredibly helpful. They allow the pollen to link to the anti-pollen antibody, and even allow histamine to be released, but they block the impact of histamine and so block any allergic reaction! There are two types of antihistamines: oral and ocular- swallowed or dropped in the eye. The common oral antihistamines- claritin, zyrtec, and allegra- are non-sedating and each last 24 hours a dose. Benadryl is also oral, but is more powerful, lasts only 4 hours a dose, and does make people sleepy, and young children agitated. There are also eyedrop antihistamines that are very safe and are great for eye symptoms- these include Naphcon and Opticon (over the counter) and Patanol (by prescription)
- Antileukotrienes- these drugs like antihistamines block all allergic reactions. The main drug used in this category is Singulair or Monteleukast.
- Steroids- Steroids are a very potent treatment option as they work by wiping out the mast cell, the cell that the allergy antibody attaches to, and that is the source of all the allergic reactions. No mast cell, no allergic reactions. The main steroids used are nasal and lung inhaled steroids and steroid creams for eczema.
The usual strategy is to start with antihistamines and/or Singulair. If allergic symptoms remain problematic then steroids are added- usually inhaled steroid for the nose and or lung.
Usually these steps suffice. But sometimes spring allergies are so severe that further steps need to be considered, including allergy shots which can actually change the production of the person's allergic antibody.
Bottom Lines
- Every spring we seem surprised at just how dramatic spring hay fever is. TV and magazines often dramatize the sudden flare of hay fever with headlines such as, "This is the worst allergy season in **** years." But the fact is that every spring there is a very dramatic burst of suffering from pollen allergies, to don't be surprised when it hits.
- Allergies are a type of inflammation. One that is marked by itch, and always be reaction to something outside the body, but once the itchy inflammation passes, usually no lasting harm is noted.
- Classic allergy always involves the sequence of some specific item you are allergic to connecting to an E-class of antibody, thereby opening up a mast cell to discharge a slew of inflammatory chemicals- histamine for example. To be allergic to something means you have that E-type of antibody and that it is loaded on mast cells, ready to go if that item contacts the antibody.
- Spring allergies occur from such a reaction to pollen. Mainly tree and grass pollens.
- Pollen allergies cause reactions where air hits the body- eyes, nose, throat, and lungs. And, it should be mentioned sometimes an itchy skin rash.
- First line of treatment usually is an antihistamine. Oral for nose, throat, and lung issues, ocular for itchy eyes. These include once-a-day forms like Claritin, Zyrtec, and Allegra. For more severe reactions, Benadryl should be used every 4 hours. For eye reactions, antihistamine eye drops are very helpful.
- If antihistamines and/or Singulair fail to help well enough, steroids come next. Nasal steroids include Flonase, Flovent, Rhinocort, Nasacort. These are essentially identical medications and very interchangeable, and many are now over the counter. Nasal steroids are helpful for nasal symptoms. For wheeze and cough we turn to inhaled steroids such as Flovent, Asmanex, and Pulmicort.
- The use of antihistamines, Singulair, and and/or steroids (nasal, lung) help the vast majority of people with spring allergies. But, for those few who are not helped, other interventions are available as well.
So, here is to a glorious spring and to your health!
Dr. Arthur Lavin
*Disclaimer* The comments contained in this electronic source of information do not constitute and are not designed to imply that they constitute any form of individual medical advice. The information provided is purely for informational purposes only and not relevant to any person's particular medical condition or situation. If you have any medical concerns about yourself or your family please contact your physician immediately. In order to provide our patients the best uninfluenced information that science has to offer,we do not accept samples of drugs, advertising tchotchkes, money, food, or any item from outside vendors.
No comments:
Post a Comment