Allergen immunotherapy works in much the same way as other types of immunotherapy, such as vaccines. A small amount of an allergen is injected into the body of someone who is allergic to that substance. The exact amount used may depend on the severity of the allergy. Once it is injected, the person’s immune system begins creating antibodies to attack and desensitize the body against the allergen. Over time, the amount of each allergen is increased. Allergen immunotherapy is most effective when used over the course of three to five years.
Children may have the most to gain from allergen immunotherapy. It has been suggested in some studies that weekly or monthly injections may prevent asthma symptoms or prevent asthma in children who have allergies. Adults may also benefit from the use of allergy shots if medications and other treatments have been ineffective, or if side effects to those treatments are severe. In most cases, allergen immunotherapy consists of two phases.
The first phase, or buildup phase, lasts for several months. During this time, patients are given shots several times a week in order to build up the body’s immune response. After this is complete the second phase, or maintenance phase, is used to help keep the response going. This requires shots once a month and the entire phase generally lasts three to five years. Both phases are necessary to achieve maximum results.
Once allergen immunotherapy has been completed, patients often have fewer symptoms. In some cases, symptoms may be gone entirely unless the person is exposed to abnormally high levels of certain allergens. Allergy shots are used for both seasonal and indoor allergies, as well as insect stings. The most common allergies involve pollen, pet dander, dust mites, mold, and bee stings. Allergen immunotherapy is not used to treat food allergies.
Before allergen immunotherapy is used, patients must undergo tests to determine if symptoms are caused by allergies and which allergens are to blame for those symptoms. Symptoms are usually alleviated slowly over the course of the first year of treatment, although every patient is different, so this may take a shorter or longer period of time. Until the maximum effect has been achieved, patients may still be required to use any existing allergy medications if available.
Children should be taken to an allergy specialist who is trained to work with kids. Getting multiple shots a week can be traumatic for young children, especially those who are too young to understand what the injections are for. The office atmosphere should be one that encourages them to relax, and toys or videos may be provided for distraction. Older children should be given a full explanation of their symptoms and treatments. In most cases, children become accustomed to the frequent shots.
