Dear Doc: I came to see you for a severe spring tree pollen allergy. Those symptoms are much better with my allergy shots; however, I seem to be bothered a lot by physical stimuli such as weather fronts and temperature changes. Is this also allergy?
The unequivocal answer to your question is yes – and no.
Let’s start with what is well-known about allergy. We know it is an immune response to exposure to a protein molecule, such as oak pollen, which causes your spring symptoms. The presence of oak pollen leads to release of allergic molecules such as histamines that mediate typical allergic symptoms.
Of course, there is no foreign protein involved with physical stimuli, but rather a change in barometric pressure, temperature or humidity. Effects of these stimuli actually are neuronal-based symptoms of allergy. Believe it or not, the nerves of our nervous system can cause or contribute to myriad symptoms, including: red/itchy eyes, sneezing, nasal congestion, runny nose, cough, wheeze, airway mucus, GI symptoms and itchy, red, swollen skin.
The process involved: These chemical mediators, such as histamine, also stimulate the sensory nerves. These nerves carry a signal to the brain causing outgoing responses that trigger the sinus congestion and extra-nasal mucus that you experience from the weather change.
Non-allergic individuals can experience modest neuronal responses to physical stimuli, but allergic individuals are much more severely buffeted by a given stimulus. Reason: the sensory nerve input “up-regulates” the central nervous system’s outgoing response, making it much stronger than it otherwise should be.
These neuronal-based issues are currently under intense scrutiny in an attempt to “down-regulate” the sensory feedback and, thereby, lessen symptoms.