What Are Allergy Shots and Immunotherapy?
Allergy shots is the only treatment of allergy known to have a definite and final cure on allergy. Although the effectiveness is not 100% in all individuals, allergy shots and immunotherapy is very effective against allergies caused by insects bites, grass, dust and pollen particles.
Is There Any Preparation for Allergy Immunotherapy?
Before allergy shots are prescribed, the patient needs an evaluation by an allergist, a doctor who specializes in diagnosing and treating allergies. Skin tests (a procedure by which the allergist injects a tiny amount of allergen under the patient’s skin and observes the reaction) will be used to definitely establish the need of immunotherapy. Also, allergy shots are recommended if the patient suffers from allergic reactions to a particular allergen for more than three months per year (for example rhinitis).
No special preparation is needed for any immunotherapy session. The patient needs to be monitored for about an hour after receiving the shots just in case severe systemic reactions or anaphylaxis occurs.
How Is Immunotherapy Performed?
Immunotherapy is defined as “the administration of gradually increasing quantities of specific allergens to patients with IgE-mediated conditions until a dose is reached that is effective in reducing disease severity from natural exposure.” (Huggins and Looney,. 2004). Basically, increasing amounts of known allergens are injected into the patient (gradually over the course of several months) to increase the tolerance to those allergens. As tolerance increases, the patient receives a maintenance dose once in a while. The own patient builds resistance to the allergen by his (or her) own immunological system.
The complete treatment involves two definite periods. The first one may last 3 to 7 months of weekly injections. At the start, very low concentrations are injected to the patient. Afterwards, each therapy increases the amount of allergen injected. The dose is increased accordingly to the reaction of the patient. In the second phase (4-5 years) the patient receives a maintenance dose once each month. The allergist will determine how long the first or second phase will last. He can also discontinue the treatment if symptoms are not alleviated after a few months or if they increase with the treatment.
What Are the Risks of Allergy Shots?
Allergy shots are not exempt of risks. Generally people tolerate the treatment well and only local reactions (a local redness or rash) may be present in the first few injections. However, in highly sensitive patients, there may be severe reactions that may mimic the allergies that the treatment is trying to eradicate. Reactions may include difficulties in breathing, wheezing, asthma – like symptoms, and generalized rashes. Anaphylaxis is also possible with immunotherapy (although rare). An anaphylatic shock is life threatening and can be reversed easily with proper emergency care. That is why allergy shots require a patient observance time after injections have been administered.
Allergy shots: Mayo Clinic. https://www.mayoclinic.com/health/allergy-shots/MY01158
Huggins, J. L., Looney, J. (2004). "Allergen Immunotherapy," Am Fam Physician. 70(4): 689-696. https://www.aafp.org/afp/2004/0815/p689.html
Allergy Shots. WebMD. https://www.webmd.com/allergies/guide/shots