Do many allergy medicines compromise the immune system?

It’s allergy season again. Thanks to an unusually cold, wet winter triggered by a strong El Niño current, all the trees this year blossomed at the same time, flooding the air with pollen. Many allergy sufferers are having a miserable spring.

There are numerous OTC and prescription drugs on the market to help fight off the effects of allergens like pollen. They work by suppressing the body’s natural reaction to histamines and/or leukotrienes. But histamines and leukotrienes are a natural part of the body’s immune response to foreign materials invading it. How much does suppressing them also suppress normal immune defenses?