Between 30 and 40 million Americans are allergic to something. Cat fur, edible nuts, bee stings, shellfish, fabric softener, certain food preservatives and furniture polish have been known to trigger allergic reactions.
Such reactions range from a vague discomfort in the nose or eyes to, in a few cases annually, death.
No season is immune from allergies altogether, but prime time for hay fever begins with the return of leaves to trees. From early March through May, and again throughout the summer, trees, plants, molds and weeds will be responsible for the misery of many people with allergies.
The root of those woes is pollen. Or, more precisely, it is the protein contained in the pollen. The body's immune system sees the protein as a disease-causing invader, much like a bacteria or virus, and reacts by releasing histamine.
Histamine, which is secreted by mast cells found in almost every tissue of the human body, widens blood vessels and makes them permeable so that natural immune agents can reach the site of injury or infection. But with allergies, the body not only misidentifies the threat, it also overreacts and releases far too much histamine.
For some the result is all too familiar; swelling, a runny nose and watery eyes. Persons allergic to tree pollen can expect a visit from those symptoms from April through May. From Memorial Day to mid-August is the season for grass pollen, and ragweed - the worst of this lot - comes on the scene around Labor Day.
To what do the nearly 20 percent of Americans who suffer from allergies owe their affliction? A combination of nature and nurture.
You are born with the genetic makeup that will predispose you to allergies but may never know if you are not exposed to the right allergen. Your genes may make you allergic to ragweed. If you live all your life in Europe, where there is no ragweed, you would never develop the allergy. Thus, the best thing for people with allergies is to avoid the allergen if they can.
That measure fails with pollen because it is almost everywhere - some has been found hundreds of miles at sea. You can minimize your exposure by staying indoors in an air-conditioned environment. That usually is not completely effective in controlling symptoms, so often some medication is required.
Remedies for the travails of bay fever abound, and more may soon hit the over-the-counter drug market. Yet many of these cures cause other problems or, if used incorrectly, exacerbate the allergic reaction.
The first thing to understand is what these medications are and what they do. Allergy medications in the United States commonly contain either an antihistamine or a decongestant, or both. An antihistamine is a synthetic drug intended to prevent the mast cells from secreting histamine.
Decongestants, frequently found in nose sprays, shrink swelled mucous membranes by contracting the blood vessels. The two things people must understand about over-the-counter drugs are:
• Usually they are not very strong, which makes them useful only for persons with mild allergies.
• Even though they are not very strong, they can cause reactions with other medications or other disease processes. For example, both thyroid and prostate conditions are adversely affected by many over-the-counter allergy treatments.
Side effects, such as drowsiness from antihistamines or insomnia and heart palpitations from decongestants, are also common. And nasal sprays may nave a rebound effect if used for more than a few days. With overuse, the spray will cause the nasal passages to swell up, requiring more frequent use to achieve shorter periods of relief.
