Immunotherapy











About Immunotherapy



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Immunotherapy is an allergy immunology treatment that is individually prescribed and administered by a physician or allergist. It typically involves injecting patients with small amounts of allergens (proteins and glycoproteins) over an extended period of time. Patients are not injected with these allergens into the veins or muscles; the injection is administered under the skin.

The allergen dosage that patients receive is gradually increased until a patient has a high enough tolerance level that he or she no longer exhibits a reaction to the specific allergen. The extracts that doctors use to inject patients with are referred to as “allergen vaccines,” a term proposed by the World Health Organization in 1998.

Studies have shown that immunotherapy is effective with various types of allergies, including: asthma, conjunctivitis, and rhinitis. Double-blind, scientific trials have demonstrated that patients who received treatment over a four year period experienced a significant reduction in allergy symptoms, as well as a decrease in the anti- allergy medication that they used previously. Some reports have suggested that children who receive this treatment for rhinitis may have a reduced incidence of asthma later in their lives.


Two Phases of Immunotherapy



When patients progress through their immunotherapy treatment regimen, they begin with a “build-up” phase, and they eventually reach a “maintenance” phase. We will describe each phase below.

In the build-up phase, patients receive allergen injections of gradually increasing dosages. They receive injections between once and twice per week during this phase, until an effective therapeutic dosage is reached. The duration of this phase varies between patients but it generally lasts up to six months.

When a patient is done with the build-up phase and a therapeutic dosage is reached, the maintenance treatment phase begins. Of course the allergen vaccine dosage is different for each patient, as this depends on their sensitivity to each allergen. However, there is now a longer interval between injections, which usually take place every two to four weeks in this interval. The maintenance phase of treatment may last for a period of three to five years, but it is hoped that therapeutic benefit will be seen after twelve months on this phase.


Immunotherapy Effectiveness



Allergy shots can prove to be a more effective allergy treatment than medication, since it is a treatment that can actually halt the progression of allergies, whereas medications such as antihistamines simply mask the symptoms. Patients must realize, however, that a three to five year period of injections may be necessary in order to realize benefits that will continue long-term. It is also important to understand that allergy shots do not work for all allergy patients; it may be ineffective or only partially effective for some.

This allergy treatment is not considered to be an effective treatment for food allergies or allergies to medication. It has been shown to be more effective for environmental allergens that are difficult to avoid, such as:


• Mold spores

• Dust mites

• Dust

• Cat dander

• Dog dander

• Cockroach

• Stinging insect venom

• Tree pollen

• Grass pollen

• Weed pollen



Also, immunotherapy has been shown to be more effective when the treatment regimen begins early in a patient’s life, or if treatment begins soon after an allergy manifests.





Side Effects



Patients may experience reactions to allergy shots, local allergic reactions which are considered to be mild, or they may experience systemic reactions which are more serious. Local reactions occur more frequently than systemic reactions and involve pain, redness, and swelling where the allergen vaccine was injected. Conversely, systemic reactions are cause for concern.

Systemic reactions can manifest with allergy shot side effects such as hives, sneezing, or congestion, but these reactions can appear in a more serious form known as anaphylaxis. In anaphylaxis, life threatening events can occur such as swelling of the throat and tightness of the chest. These reactions usually occur within thirty minutes of injection and they require immediate treatment by a physician.

Because of the side effects patients can experience from allergen vaccines, allergy injections are given in a doctor’s office or medical facility where there are personnel equipped to recognize and treat such reactions. The current protocol is for patients to undergo a period of observation of about thirty minutes after their injections. Some patients are instructed to carry injectable epinephrine, or an epiPen, in the event of an anaphylactic episode.


Safety



Allergen immunotherapy is considered to be a safe treatment for allergies, although adverse reactions have been reported in a number of patients. One researcher found that serious reactions due to this treatment occurred in less than one percent of the patients who received treatment.

Because of the risks associated with treatment, patients who have serious health conditions such as heart problems or hypertension are not candidates for immunotherapy. Young children may also not be candidates for this treatment since they could have trouble communicating the fact that they are experiencing an allergic reaction after their injection.


Is Immunotherapy for You?



This is a question that is best answered by your physician. However, there are some guidelines that are generally followed in making this decision. When evaluating whether immunotherapy is right for you, consider the following factors:


• Consider this treatment if you have tried allergy medication such as antihistamines and they did not provide you with adequate relief

• Allergy shots may be the better option for you if you’ve tried allergy medications and you experience unpleasant side effects from taking the medicine on a daily basis. click here if you would like to explore some effective natural alternatives to immunotherapy

• This treatment may be a more cost effective option for you, since the cost of allergy medication over an extended period of time may be prohibitive for some patients. Also, insurance companies are no longer as likely to cover the cost of standard allergy medications since there are now viable over-the-counter options that compete with prescription medicines

• You may choose this treatment because you feel that allergy medicine merely masks the symptoms of your allergies, whereby you would rather opt for a solution that can actually eliminate your allergies permanently

• Consider allergy injections if you have experienced anaphylaxis (dangerous allergic reactions) to an allergen, such as stinging insects (bees, fire ants, etc.)


Sublingual Therapy



Sublingual immunotherapy, or SLIT, is a widely used allergy treatment in Europe and other countries, but lately it seems to be getting some serious attention from physicians in the U.S. SLIT is done at home on a daily basis, where individual allergens are mixed with a glycerin solution and held under the tongue or swallowed. Although the allergen dosages are much higher than that of subcutaneous injections, SLIT is considered to be the safer treatment.

In a survey done by the American College of Allergy, Asthma, and immunology, it was found that subcutaneous allergy injections resulted in about five near fatal allergy reactions per 2.5 million injections. Conversely, studies of SLIT therapy indicate no life threatening episodes of anaphylaxis, however some urticaria and asthma incidents did occur. Considering the larger allergen dosages used in SLIT, it is not surprising that patients may experience gastrointestinal distress after their treatments. One other disadvantage of SLIT is that it is about ten times more costly than subcutaneous allergy shots.

Greer Laboratories, a company in North Carolina, is a supplier of allergy immunotherapy testing and treatment materials. Greer conducts research on SLIT and has studied its effects with patients who were allergic to ragweed and other substances. Greer has already applied for FDA approval of its SLIT therapy. Currently, Greer provides the allergy extract for a Duke University study that is evaluating the effectiveness of SLIT for peanut allergies.




References


Baines, Emma. Behind the Headlines: A cure for allergies in three years? GP, Sept, 2006, p14.

Bates, Betsy. Is allergy control heading under the tongue? Skin & Allergy News, Feb 2006, p50

Kwong, Frank & Cook, Bruce. The Complete Allergy Book. Illinois: Sourcebooks Inc., 2002.

Selecting patients for allergen immunotherapy. Journal of Respiratory Diseases, Sept. 2004, p390.

Sublingual Immunotherapy Relieves Allergic Rhinitis. The Clinical Advisor, Feb 2007, p168-169.