The most basic treatment of allergy, once an allergen has been identified, is to eliminate it. This may mean avoiding certain jewelry and cosmetics, deleting specific foods from the diet, and alerting physicians about drug allergies. In the case of an allergen in the environment, such as dust, pollen, and mold, a thorough house cleaning along with other careful preventive measures will cut down on the exposure. However, if the allergen is seasonal pollen, moving may not be the solution since there might be tree or weed pollens in the new location which could bring about the development of another equally distressful allergic reaction.

Drug treatment has long been a cornerstone of allergy treatment. Antihistamines and/or decongestants (for the nose) and bronchodilators (for asthma) counteract the symptoms caused by chemicals released by the body's immune system in an allergy attack. There are other drugs, both pills and nasal sprays, which can prevent the release of these inflammatory chemicals or suppress the immune reactions themselves. Steroids of the cortisone family can suppress allergic reactions, but often there is the risk that the patient may develop significant side effects when taken for prolonged periods of time. Steroid nose sprays and inhalers will often relieve allergies and not cause side effects.

When avoidance and/or medication are not adequately controlling symptoms, immunotherapy is the best treatment option. Traditional immunotherapy is via injection (allergy shots). The newer sublingual technique (allergy drops) is proving effective and in some cases a better alternative than injection immunotherapy.

Before immunotherapy is begun, allergy testing determines the antigens to which the patient is most sensitive. The appropriate allergens and their doses must be determined individually for each patient. Skin testing (placing a minute amount of the allergen under the skin) and RAST (blood test for specific allergies) are both widely used for this purpose. Both detect the substances to which a person is allergic, as well as the degree of sensitivity, which helps determine the initial treatment dose.

Immunotherapy can bring significant relief within a few months, but may require as long as 4 to 5 years. In some cases, unfortunately, it may be necessary to continue the treatment indefinitely. Over 80% of the patients who receive immunotherapy experience significant improvement or complete relief of their symptoms.