Wednesday, March 7, 2012

Seasonal Allergies: Immune modulation and desensitization.

Here in Victoria, one of the first signs of spring are the beautiful cherry blossoms lining many of our streets.  And then the close second is the multitudes of people wandering around with bloodshot, watery eyes, chronic sniffles and itchy red noses.

Seasonal allergies are a real struggle for many people.   Allergies start early in the Spring with tree and bloom pollens, closely followed by Summer grasses and then in the Fall with Molds and Dust.  A good portion of my patients take an antihistamine daily all year just to function comfortably.  Fortunately, there are many many options for support.  Allergies occur when the immune system gets diverted down a pathway that starts to see normal environmental proteins (pollens and dust or food proteins) as foreign invaders instead of inert substances.  The immune system goes down a very specific pathway called the TH2 pathway. In this pathway, exposure to the allergen causes activation of MAST cells, which release histamine and the activation of Eosinophils, which are the white blood cells associated with the allergic response.  It is believed that this pathway evolved for the purposes of protecting us against parasites but since we don't spend as much time living off the land as we previously did, it got diverted into attacking other large molecules - even benign ones like pollens and dust.

Fortunately, there are lots of options for supporting the system against allergies.  One way is to desensitize the body against the allergens.  This is called building tolerance.  Exposing the body to very tiny amounts of the allergens, especially through the digestive system, triggers the body to inactivate the immune cells that were primed to that allergen.  Over time, this effectively turns off the allergic pathway triggered by that allergen.  Allergist and Naturopathic Physicians (at least in BC) can take advantage of tolerance by doing allergy shots or sublingual allergy drops.  Other substances act along the pathway to shift away from the TH2 pathway (as some probiotics do) or to calm the MAST cells (like Quercitin).  There are quite a lot of good herbs that can be very helpful for allergy season and a Naturopathic Physician or qualified Herbalist can help you choose an appropriate formula.  Have a good spring.

As always, feel free to send me an email if you have any topics you'd like me to discuss.
Dr. Kellie

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