No, if you are allergic to a substance such as Chinese elm, you will not overcome your allergy by repeatedly inhaling Chinese elm pollen into your nose or lungs. So then, how can a series of injections allergen relieve your allergy symptoms?



Allergen immunotherapy is almost like a vaccine. Your body responds to the injected amounts of a particular allergen, given in gradually increasing doses, by developing an immunity or tolerance to the allergen(s).

As a result of these immune changes, immunotherapy can lead to decreased, minimal or no allergy symptoms when you are exposed to the allergen(s) included in the allergy vaccine.

What is the Immunotherapy Process?

There generally are two phases to immunotherapy: a build-up phase and a maintenance phase.

Build-up phase is the initial period of receiving injections with increasing amounts of the allergens. The frequency of injections during this phase generally ranges from 1 to 2 times a week. The duration of this phase depends on the frequency of the injections but generally ranges from 3 to 6 months.

Maintenance phase begins when the effective therapeutic dose has been reached. The effective maintenance dose is different for each person, depending on individual sensitivity (how 'allergic they are' to the vaccine) and their response to the immunotherapy build-up phase. Once the maintenance dose is reached, there will be longer periods of time between immunotherapy treatments. The intervals between maintenance injections, generally ranges from every 2 to 4 weeks. Your allergist/immunologist will determine what range is most appropriate for you.

Reduced allergy symptoms are not normally immediate or dramatic. Improvement with immunotherapy is usually a progressive, cumulative effect that happens slowly throughout the immunotherapy treatment period. Effectiveness of immunotherapy appears to be related to length of treatment and the dose of the allergen.

Does Immunotherapy Ever Fail?

Most individuals receive at least some benefit from the treatment. However, it is 100% guaranteed to be effective for everyone. Failure to respond to immunotherapy may be due to several factors including:

Inadequate dose of allergen in the allergy vaccine.

Missing allergens not identified during the allergy evaluation.

High levels of allergen in environment (i.e. inadequate environmental control).

Significant exposure to non-allergic triggers (i.e. tobacco smoke).

If there is no improvement after a year of maintenance immunotherapy, possible reasons for failure to respond should be explored. If no apparent reason is found then discontinuation of immunotherapy should be considered and other treatment options should be pursued.

How Long Does Immunotherapy Last?

When immunotherapy happens successfully, maintenance treatment is generally lasts around 3 to 5 years. The decision to stop immunotherapy should be thoroughly discussed with your allergist/immunologist after 3 to 5 years of treatment. Some individuals may experience long-lasting remission of their symptoms, but others may relapse after discontinuing immunotherapy. Therefore, the decision to stop immunotherapy is an individual one, after consulting with your allergist/immunologist.

Are There Risks or Side Effects?

A report from the Mayo Clinic on 79,593 immunotherapy injections over a 10-year period showed the incidence of adverse reactions to be less than two-tenths of 1 percent (0.137 percent). Most of these reactions were mild and responded to immediate medical treatment. There were no fatalities.

However, it is possible to have an adverse reaction. There are two types of reactions that can occur with immunotherapy: local and/or systemic reactions.

Local reactions are relatively common and can show up as redness and swelling at the injection site. This may happen immediately, or a few hours after the treatment.

Systemic reactions are much less common. Systemic reactions are usually mild and respond rapidly to medications. Symptoms can include increased allergy symptoms such as sneezing, nasal congestion or hives. Rarely, a serious systemic reaction, called anaphylaxis, can develop after an immunotherapy injection. In addition to the symptoms associated with a mild systemic reaction, symptoms of an anaphylactic reaction can include swelling in the throat, wheezing or a sensation of tightness in the chest, nausea, dizziness or other symptoms. Systemic reactions require immediate treatment. Most serious systemic reactions develop within 30 minutes of the allergy injections and this is why it is usually recommended that you wait in the office for 30 minutes after your allergy injections. It is for your own safety. Allergist/immunologists are trained to monitor for reactions, as is members of his or her staff able to identify and treat systemic reactions.

Guidelines for safe and effective immunotherapy

Although side effects are rare, the American College of Allergy, Asthma & Immunology offers the following guidelines to ensure the safety of any patient receiving immunotherapy:

Only an allergist/immunologist or other physician who is expertly trained in the therapy should prescribe immunotherapy.

Immunotherapy should be administered under the supervision of an allergist-immunologist or other physician specifically trained in immunotherapy, the early signs and symptoms of anaphylaxis, and appropriate emergency procedures and medications. Patients must be suitably selected for immunotherapy. Immunotherapy should be given only in facilities equipped to treat anaphylaxis. The health status of the patient should be evaluated prior to every injection. Patients who are acutely ill, especially with asthma or respiratory difficulties, should not receive immunotherapy until their disease is stabilized. Patients should always be asked about current medications prior to immunotherapy, to avoid interactions with beta-blockers and other conflicting medications. Patients must wait at the health care facility a minimum of 20 minutes after an allergen injection. The time period may be extended for high-risk patients.

Who Decides If a Patient Should Receive Immunotherapy Treatment?

Ultimately the decision about whether or not to receive immunology treatment is up to the individual and their family, although the allergist has the expertise to help his or her patient understand what options are most appropriate according to their individual needs.