What is the treatment for allergies?
Avoidance of identified allergens is the most helpful factor in controlling allergy symptoms. Attempts to control the environment and avoidance measures often significantly aid in resolving symptoms. However, allergy avoidance is often not easy. A thorough discussion with your physician is needed, and control measures may be required daily.
If avoidance is not possible or does not relieve symptoms, additional treatment is needed. Many patients respond to medications that combat the effects of histamine, known as antihistamines. Antihistamines do not stop the formation of histamine, nor do they stop the conflict between the IgE and antigen. Therefore, antihistamines do not stop the allergic reaction but rather protect tissues from the effects of the allergic response.
The first-generation antihistamines, such as diphenhydramine (Benadryl), chlorpheniramine (Chlor-Trimeton), dimenhydrinate (Dramamine), brompheniramine (Dimetapp and others), clemastine fumarate (Tavist, Allerhist), and dexbrompheniramine (Drixoral) frequently cause mouth dryness and sleepiness as side effects.
Newer, so-called "non-sedating" or second-generation antihistamines are also available. These include loratadine (Claritin), fexofenadine (Allegra), cetirizine (Zyrtec), and azelastine (Astelin Nasal Spray). In general, this group of antihistamines is slightly more expensive, has a slower onset of action, is longer acting, and induces less sleepiness. Many of these medications are available over the counter.
Discuss with a physician other antihistamine side effects that occasionally occur (for example, urine retention in males, fast heart rate, and others). Always discuss the potential side effects of any medication with a physician and/or pharmacist.
Decongestants help control allergy symptoms but not their causes. Decongestants shrink the swollen membranes in the nose and make it easier to breathe. Decongestants can be taken orally or by nasal spray. Decongestant nasal sprays should not be used for more than five days without a doctor's advice, and if so, usually only when accompanied by a nasal steroid. Decongestant nasal sprays often cause a so-called "rebound effect" if taken for too long. A rebound effect is the worsening of symptoms when a drug is discontinued. This is a result of a tissue dependence on the medication.
Some people with allergies need specialized prescription medications such as corticosteroids, cromolyn, and ipratropium (Atrovent) nasal sprays. These nasal sprays do not cause the rebound effect noticed with decongestant nasal sprays. Cortisone nasal sprays are very effective in reducing the inflammation that causes swelling, sneezing, and a runny nose. Cortisone can also decrease the formation of many chemicals involved in the allergic response. Many cortisone nasal sprays are on the market through prescription only. Intranasal steroids are typically the first-line medications for patients suffering from persistent allergies. Fluticasone (Flonase) is one medication available over the counter.
Cromolyn is also an anti-inflammatory medication available over the counter. Although cromolyn is not as potent as cortisone, it is very safe. Cromolyn must be used well in advance of anticipated allergy symptoms to be useful. Ipratropium (Atrovent) nasal spray is available for drying a wet runny nose. It will not prevent allergic reactions. This is an atropine derivative and although usually very safe, a person sensitive to atropine should be cautious when taking this drug.
Montelukast (Singulair) is an inhibitor of leukotriene action, another chemical involved in the allergic reaction. This medication is used for therapy of asthma and has also been approved for treatment of allergic rhinitis, but it is not a first-line therapy. It has been shown to be most effective in those for whom significant congestion is a primary complaint. It may also be used in some cases together with antihistamines.
If antihistamines and nasal sprays are not effective or not tolerated by the patient, other types of therapy are available. Allergy desensitization or immunotherapy may be needed. Allergy immunotherapy stimulates the immune system with gradually increasing doses of the substances to which a person is allergic. Because the patient is being exposed to the allergy-inducing substance, an allergic reaction can occur and this treatment should be supervised by a physician. Although the exact way allergy desensitization works is not completely known, allergy injections appear to modify or stop the allergic reaction by reducing the strength of the IgE and its effect on the mast cells. This form of treatment is very effective for allergies to pollen, mites, cats, and especially stinging insects (for example, bees). Allergy immunotherapy usually requires a series of injections (allergy shots) and takes three months to one year to become effective. The required length of treatment may vary, but three to five years is a typical course. Frequent office visits are necessary.
The duration of the effect of allergy immunotherapy should last many years, if not a lifetime. Although rare, serious allergy reactions can occur while receiving allergy injections. One cannot predict who will have a severe reaction. Even after years of receiving allergy shots, a patient can experience a reaction.