After a long harsh winter, spring is finally here. Flowers are blooming, wind is mild, and everybody is happy. Almost. For significant number of Bostonians, spring also means the beginning of sneezing, runny nose, itchy eyes, itchy noses, coughing and fatigue. They are sufferers of allergic rhinitis, or hay fever, or in Chinese, “disease of flowers pollens”.

Sneezing that is repeated and prolonged is the most common mark of the hay fever sufferer. A stuffy and watery nose is also a main sign of hay fever. Other symptoms include redness, swelling and itching of the eyes; itching of the nose, throat and mouth and itching of the ears, or other ear problems. Breathing difficulties at night due to obstruction of the nose may interfere with sleep.

In the U.S., 9 to 40 percent of the population may have some form of allergic rhinitis. Thus, if it is assumed that 20 percent of the population is affected, then approximately 60 million people may suffer from the disorder. For whatever reason, people living in Boston are especially hard hit. One friend of mine had no symptoms of allergic rhinitis after living in New York for 9 years. But the first summer in Boston, he was greeted with the annoying disease and suffers from it ever since. It is estimated that more than 40% of Chinese living in the Greater Boston area suffers from allergic rhinitis.

The symptoms of allergic rhinitis are caused by reaction of the body after the nasal mucosa is exposed to the pollens. In the spring time, the common antigens are tree and grass pollen (therefore the name: rose fever). In the fall, ragweed pollens are the principle culprits (therefore the name: hay fever). ragweed is the plant that causes the most hay fever. The pollens have to be small enough to breath into the airways. The heavy coat of yellowish pollens on our cars during spring time never cause allergic rhinitis because they are too heavy to breath into the nose. After the pollens are inhaled into the nose, they trigger the immune response from the body after they bind to IgE receptors on the surface of Mast Cells, a particular type of cells responsible for body’s defense against foreign body invasion. In the familiar environment of our home towns, we grew up with all types of pollens. Therefore, our body would not over-react after their inhalation. In contrast, we probably have never been exposed to the pollens similar to those in the Boston area. Therefore, the body reacts by producing more and more mast cells each time it exposes to the new pollens. With time, that usually takes about three years in a susceptible person, the body builds up so many mast cells that the next exposure to the pollens will trigger massive release of histamines and other cytokines, including leukotrienes and interleukins. Those mediators in turn cause runny nose, sneezing, itchiness, congestion and coughing.

The following are identified risk factors for allergic rhinitis: family history of atopy (such as asthma, eczema, or allergic rhinitis), male sex, birth during the pollen season, presence of allergen specific IgE. Everyone is different in terms of how his/her body reacts to the pollens because of their different sensitivity. Also Somebody who has severe symptoms in one place would have no symptoms after they move to a new area because of change of types of pollens.

Allergic rhinitis is associated with significant morbility and expense. Affected individual have a quality of life significantly worse than otherwise healthy ones. In addition, only a relatively small number of patients undergo remission over time. It is estimated that allergic rhinitis causes a total indirect and direct cost of $7 billion per year.

We will talk about how to treat and prevent the symptoms of allergic rhinitis on our next issue.

Pollan Count: A pollen count is the measure of the amount of pollen in the air. Pollen counts are commonly included in local weather reports. The counts are usually reported for mold spores and three types of pollen: grasses, trees and weeds.

The count is reported as grains of pollen per square meter of air collected over 24 hours. This number represents the concentration of all the pollen in the air in a certain area at a specific time. The pollen count is translated into a corresponding level: absent, low, medium or high.

In general, a “low” pollen count means that only people extremely sensitive to pollen will experience symptoms. A “medium” count means many people who are sensitive to pollen will react and a “high” count means most people with any sensitivity to pollen will be affected.

Although the pollen count is approximate and fluctuates, it is useful as a general guide when you are trying to determine whether you should stay indoors to avoid pollen contact.