There are periods of the year where plants release clouds of pollen. Pollen is a plant structure which houses a sperm generator; it is found and produced in male plant parts (anther or cone). It houses a tube nucleus and a generative nucleus inside a protective, vegetative covering. It is essential in the fertilization of plants and is transferred from the source plant to the female receiving portion (stigma) of another via several means including wind, birds, insects, and even humans. Plants that favor dispersal by wind are called anemophilous plants (wind loving) while those that are dispersed by insects are named entomophilous plants (insect loving).
A person’s immune system is designed to keep microorganisms, toxins, and other foreign bodies from doing harm. Allergies are responses or reactions of our immune system to foreign bodies or threats. These responses are sometimes excessive and may continue even after the threat is removed. Allergens trigger allergic reactions, making the body’s immune system respond in exaggerated ways. Most allergens are mild to harmless in a normal person, triggering no to mild immune response. A normal person’s immune system would react to a foreign body by releasing IgM, IgG, IgA, IgD antibodies and cells. After the allergen is neutralized, these antibodies and cells are no longer released. Allergic persons release high amounts of IgE that remember the particular allergen or substance that triggered the reaction. Eventually, every time the specific allergen is encountered, the body responds excessively. IgE antibodies are cause-specific, and when triggered, cause an immune response that includes inflammation, sneezing, runny nose and eyes, coughing, and even lack of breath. These symptoms are produced by chemicals such as histamine and prostaglandin.
There are many types of allergy but among the most common is allergy to pollen. Pollen allergy is also called hay fever, a term coined by Dr. John Bostock who mistakenly thought that it was hay that caused his own summer allergic episodes. Pollen allergies are usually caused by pollen produced by anemophilous plants. Due to the wind driven nature of their dispersal, these plants have lightweight, easily airborne pollen grains that are easily breathed in, and can easily come into contact with the skin, eyes, mouth and other unprotected areas.
Signs and Symptoms
Allergy to pollen exhibits many signs and symptoms and usually involves the body’s response to an attack but more severe. Pollen allergy sufferers experience runny noses and watering eyes. IgE antibody causes the release of histamine which causes irritation, itchiness, and excessive production of mucus, leading to clogged mucus membranes. Uncontrollable sneezing and persistent presence of mucus and coughing are also experienced by the allergic individual. Shiners or dark circles under the eyes and itchiness/pressure in the face and ears may also result from pollen allergy. Asthma can also occur in people with severe allergic reactions to pollen, causing shortness of breath and wheezing. When left untreated, it may lead to death.
Diagnosis
When one exhibits signs and symptoms of pollen allergy, it is a good idea to isolate what particular plant pollen causes the allergic reactions. Skin testing utilizes pollen extracts applied to a scratch or small pinprick made in the skin. Reddening or inflammation on the area confirms pollen allergy and means that IgE is being manufactured in response to the particular pollen extract. This test however is certain only for signs and symptoms in the skin and not for those of the respiratory system.
Aside from skin testing, blood tests are also available which pinpoint lgE spikes in the presence of a particular plant pollen. Also called a RAST or a radioallergosorbent test, this is more costly than the standard skin test, and results may take longer to arrive.
Prevention
Cases of pollen allergy can be prevented or minimized by taking several precautionary measures. Closing doors and windows, attaching filters to HVAC systems, and placing screens to windows should be done to minimize pollen entry into a building or house. Changing clothes and taking a shower after coming from outdoors or before sleeping would wash away pollen grains attached to your skin and clothes. It is also a good idea to wear a face mask when going to areas dense with pollen. Pets like dogs or cats may be kept indoors during the pollen season, to avoid their fur getting speckled with pollen. Other irritants which may aggravate pollen allergies should also be avoided like car exhaust, cigarette smoke, dust, and pesticides.
Treatment
Treatment of pollen allergies usually involves the use of chemicals to block the compounds produced by lgE. These include anti-histamines, decongestants, and corticosteroids. Anti-histamines counteract the excess production of histamine to lower inflammation, reduce irritation and itchiness, and clear the mucus membranes. Nasal decongestants provide relief for clogged sinuses, allowing an individual to breathe much more freely. Corticosteroids stop the production of mucus and alleviate swelling; hence, helpful for drying up the sinuses.
Immunotheraphy is used in extreme cases to reduce a person’s allergic reaction to pollen. Small, incremental doses are administered over time, increasing the person’s tolerance to the allergen.
Conclusion
Pollen allergies are very unsettling and irritating conditions. A person’s daily activities may be disrupted just because of extreme allergic reactions to a material no larger than several millimeters. Knowing what pollen you are allergic to is the first step in treating pollen allergies. Consult your doctor if at any time you exhibit signs and symptoms of pollen allergy for faster treatment.
Reference
- American College of Allergy, Asthma, & Immunology. (2006) Food allergy: a practice parameter. Ann Allergy Asthma Immunol.