If you have hay fever, the symptoms do not It will take a long time to appear after inhaling a minimum amount of pollen. It takes only a few minutes for the nose to begin to drain and sneezing (and perhaps wheezing) to begin.
Allergists call these "type I reactions" or "immediate hypersensitivity reactions". Allergic reactions to pollen, animal dander, mold spores, dust mites and other common allergens are the result of a series of responses from your immune system.
The Health System of the University of Pennsylvania divides this common type of allergic reaction into four stages.
The best way to prevent an allergic reaction is to identify the substance that causes it and avoid its "activation" in the best way possible.
Stage One: awareness
No one is born with allergies. In contrast, the first step on the road to the development of an allergy occurs when a person prone to allergies comes in contact with what is normally a harmless substance, such as pollen from the plant.
Often, such allergens first come in contact with the mucous membranes in the nose or with another part of the respiratory system. Immune cells called plasma cells respond to the presence of pollen or another allergen by forming an antibody called immunoglobulin E (IgE). The IgE molecule specifically recognizes the antigen.
Stage Two: ready and waiting
IgE antibodies adhere to immune system cells found in the tissues of the respiratory tract, gastrointestinal tract, and skin. These immune cells bound to the tissue are called mast cells. IgE antibodies also attach to immune cells called basophils in the blood. Mast cells and basophils are equipped with IgE molecules that specifically recognize a particular antigen. These molecules do nothing until you inhale or ingest or come into contact with that particular antigen again.
So, in essence, your body receives the allergen and prepares for it to enter again. For people allergic to common allergens, this usually occurs within seconds of first contact.
Stage Three: the battle
As soon as you see yourself exposed to the pollen again, the IgE antibodies bound to the immune cells will stick to the allergen. This union signals mast cells and basophils to respond as if a dangerous intruder had invaded your organism. The cells shed more than 30 chemicals, including histamine.
These chemicals cause inflammation, swelling, itching, redness and other symptoms of common allergies.
Stage Four: late phase
Some people show a delayed response or a "late phase" of their allergic reaction, between four to 24 hours after the third phase.In the case of these people, there are other types of cells of the immune system that move to the affected tissues of the third phase. These white blood cells seem to be attracted to some of the chemicals released by mast cells and basophils.
Unfortunately, recent visitors can launch their own series of chemicals that can damage nearby tissues and perpetuate the allergic reaction.
The best way you can prevent an allergic reaction is to identify the substance that triggers it and avoid its "activation" in the best possible way.
If this is not possible, an allergy specialist can prescribe medications that can relieve symptoms. You can also eliminate or reduce the severity of your allergic reaction by receiving an immunotherapy, which is a series of injections that are made over a few years to desensitize the immune system to a specific allergen.
About the author
Boyan Hadjiev, MD, is a doctor with five years of practice. He has a double certification in internal medicine (2003) and in allergy and immunology (2005).
Dr. Hadjiev graduated from the University of Michigan with a bachelor's degree in biology and an MD from the Cleveland Clinic-Case Western Reserve School of Medicine.