The following briefly summarizes some of the more common methods of diagnosing and treating seasonal allergic rhinitis. Additional information can be found in Common Allergy Tests and Medications And Treatments.
Diagnosis
Diagnosing the specific cause (s) of seasonal allergic rhinitis starts with a detailed history and physical examination by your doctor. Because so many allergy symptoms and signs can also be caused by nonallergic disorders such as infections, a deviated nasal septum, and nasal polyps, it is important to be sure that you are indeed suffering from an allergy rather than from some other condition.
The viral cold or upper respiratory infection, as doctors often call it is a common condition that must be differentiated from all forms of allergic rhinitis, including the seasonal variety. True colds produce many of the same symptoms as allergic rhinitis, but when these symptoms persist for several weeks and no other family members are affected, you are more likely to be suffering from an allergy. If your nasal problems are accompanied by a severe sore throat, muscle aches, and fever, however, you probably have an upper respiratory infection or the flu. (And, not surprisingly, poorly controlled allergic rhinitis appears to predispose some people to more frequent colds.)
Although the symptoms may be similar, the appearance of the mucous membranes of allergy sufferers differs from that of people with colds. The nasal mucosa, the lining of the nose, is typically pale and grayish in allergic disorders and the secretions are clear. By contrast, the mucosa tends to be an angry red and the secretions yellowish or greenish with true colds. The finding of so-called allergy cells, or eosinophils, in a sample of the nasal secretions is another helpful way to distinguish between the two conditions.
To confirm a suspected pollen or mold spore allergy and to pinpoint its specific cause (s), your doctor may order a variety of skin and blood tests. Scratch tests, which are used infrequently these days because of their lower rate of accuracy, consist of applying small dilutions of suspected allergens to tiny scratches made in the skin, usually of the forearm. The development of itching, redness, and hivelike swelling at a test site within fifteen to thirty minutes suggests an allergy to the test substance. Intradermal tests, which are used more frequently because of their greater accuracy, are similar to scratch tests except that the dilution of allergen is injected directly into the skin. Once again, redness, itching, and swelling indicate an allergy to a test material. After a particular allergen (or perhaps several) has been determined to be the culprit, skin tests may also be used to establish the best starting dose for desensitization (immunotherapy) therapy (which will be discussed below). Finally, a special blood test, known as the RAST, which looks for elevated levels of IgE in response to various allergens, may also be ordered.
Therapy
Therapy for seasonal allergic rhinitis may take several forms. The mainstays are the antihistamines. These medications, as their name suggests, block the effects of histamine on its target tissues, thereby reducing symptoms. More than six classes of antihistamines are available, and many such as chlorpheniramine (Chlor-Trimeton) and diphenhydramine (Benadryl) can be purchased over the counter (OTC), that is, without a doctor's prescription. Most have been around for many years and have a proven record of safety. Nevertheless, the older antihistamines often cause dryness and drowsiness, and many people cannot tolerate them for that reason. Other important side effects include urinary retention in men with enlarged prostates and aggravation of glaucoma. Two relatively newer antihistamines, astem-izole (Hismanal) taken once daily, and terfenadine (Seldane) taken twice daily both available by prescription only have proven quite effective in controlling allergy symptoms without causing grogginess. And, finally, loratadine (Claritin), the newest prescription nonsedating antihistamine, combines the convenience of once daily dosing with rapid onset of action. Quite significantly, unlike the other two agents, it has not been reported to cause heart rhythm abnormalities when taken with either oral erythromycin or ketoconazole.
Decongestants, many of which are available without prescription, are another class of very useful products. These agents work to reduce congestion by constricting the tiny blood vessels in the affected areas, thereby reducing leakage of inflammatory fluid and minimizing swelling and itching. For this reason they are also known as vasoconstrictors (vaso means blood vessels). Decongestants have the added advantage of not causing grogginess.
Two of the more common decongestants include phenylpropanolamine, the active "upper" ingredient in many over-the-counter diet pills, and pseudoephedrine (Sudafed). Side effects may include nervousness, dizziness, headaches, and high blood pressure. Individuals with a history of hypertension, seizures, or stroke should consult with their physician before taking any of these medications.
Combination antihistamine and decongestant products abound on the shelves of our pharmacies and supermarkets. Some of the more well known brands are Ornade, Allerest, and ARM, which contain both chlorpheniramine and phenylpropanolamine. Many people prefer such combinations not only for their two-pronged attack on symptoms but also because the stimulant effects of the decongestants serve to offset somewhat the drowsiness induced by the antihistamines. Nevertheless, doctors often recommend that their patients take separate antihistamine and decongestant tablets so that they may better regulate the exact amounts of each to control their effects. For those whose jobs or life-styles require absolute alertness, Seldane-D, a prescription item that contains the non-sleep-inducing antihistamine terfenadine along with the decongestant pseudoephedrine, would be a reasonable option.
Topical decongestants such as Neosinephrine nose drops or Afrin spray for the nasal mucosa and Visine-Plus for the eyes can be especially helpful for short-term use during severe attacks. Combined antihistamine-decongestant eye drops, such as Naphcon-A, Vasocon-A, or Opcon-A, may need to be prescribed by your doctor.
A word of caution: Topical decongestants for either the nose or the eyes must not be used for prolonged periods of time. The immediate relief they afford often makes it tempting to continue using them beyond the three to five days recommended, but a tolerance usually develops so that you don't achieve the same degree of relief after use. But what is worse is that many people suffer a "rebound effect" in which the nasal or eye tissue actually becomes redder, sorer, and more swollen than before. In the nose, this condition, known as rhinitis medicamentosa, is serious and is often difficult to treat. A similar situation may result in the eyes from overuse of eye decongestants.
Treatment of rhinitis medicamentosa requires immediate cessation of the offending medication. Your doctor will probably prescribe a combination of nonmedicated saline nose sprays, such as Ayr, Salinex, or Ocean Mist, to soothe and lubricate the inflamed tissues of the nose, and plain Murine or Visine for the eyes, as well as a short course of topical corticosteroids to reduce the inflammation.
Other antiallergy medications include some intended to prevent allergy attacks and others for controlling severe attacks. Cromolyn sodium, found in the medications Nasalcrom for the nose and Opticrom for the eyes, has been found useful for preventing the release of histamine from mast cells. These medications are of little use for acute attacks but may be helpful if started a few weeks before the expected beginning of the allergy season. For optimal results they must be taken from four to six times per day.
For severe attacks that cannot be controlled by either antihistamines or decongestants, whether used alone or in combination, your doctor may prescribe one or more of the various corticosteroid medications currently available. Not to be confused with anabolic steroids, the sex hormone steroids abused by some body builders and athletes, corticosteroids are instead anti-inflammatory agents. Nevertheless, because they are powerful medications with a number of potential side effects, their use demands close medical supervision. They may be administered orally (such as prednisone), by injection, or as nasal sprays (such as Vancenase, Beconase, and Nasalide) and eye drops (such as Decadron).
Lastly, if you are medically unable to use conventional allergy medications or if other forms of therapy have not proven successful, your doctor may suggest allergy shots. In brief, the principle behind this form of treatment is the stimulation of IgG antibodies in response to the injection of increasingly potent doses of an allergen usually administered once or twice weekly for several months before the onset of the allergy season. Enough IgG is generally produced in this way to effectively compete with the allergy-triggering IgE antibodies that abound during the allergy season. Unfortunately, not all people respond. But allergy shots, also called desensitization shots, are believed to be effective, at least to some extent, in as many as 80 to 90 percent of hay fever cases. The disadvantages of this form of therapy include the inconveniences of time, discomfort, and expense and the lack of guaranteed results. For some individuals, however, these shots provide the only consistent form of relief (either by themselves or in combination with the other therapies described above).
