How Do Allergy Shots Work?
Allergy shots are a form of immunotherapy. They work by exposing the body in stages to an allergen so that the body ‘learns’ not to react to that trigger. The principle is similar to that of a vaccine, which exposes the body to a small amount of a virus and then allows the body to build its immune response.
How often do you get allergy shots? Allergy shots are administered by a doctor or allergist on a regular basis, typically once or twice a week, during the build-up stage and then less frequently during a maintenance period.
Types of Allergies That Allergy Shots Can Treat
Allergy shots work well on allergies triggered by inhaled allergens, such as pollen allergies, dust allergies, and pet dander allergies. They work most effectively on the following conditions associated with allergies:
- Allergic rhinitis
- Allergic asthma
Allergy shots can also work well to limit the body’s response to a stinging insect allergy. They are typically not used to treat food allergies.
How To Prepare for Allergy Shots
There are several ways in which patients can prepare for their allergy shots. Any preparation, including taking medication, should be done in close consultation with one’s doctor or allergist.
Some doctors may recommend that a patient avoid exercise or exertion in the hours before a shot. This is due to the fact that the increase in blood flow that results from exercise can spread the injectable medication too quickly.
The allergist may also recommend taking an antihistamine in advance of a shot. Patients should also alert their doctor and nurses if they are feeling unwell before a shot, especially if there is a history of asthma.
What To Expect During Allergy Shots
Patients can expect to receive shots one to two times a week during the build-up phase. This phase of immunotherapy can take anywhere from three to six months and will vary from patient to patient. Each appointment will be relatively quick, but will involve a period of observation after the shot to ensure there is no reaction.
Shots during the maintenance stage will occur less frequently. The maintenance stage can last anywhere from 3 to 5 years, depending on the patient and condition. Patients can expect to see improvement in symptoms during both stages.
What Are the Side Effects of Allergy Shots?
As with any medical intervention, allergy immunotherapy can involve some side effects. Allergy shot side effects can include:
- Local reactions – Patients may develop redness, irritation or swelling at the site of the shot. These local reactions do not typically last longer than a few hours.
- Systemic reactions – Less common than local reactions, systemic reactions manifest through sneezing, congestion or even hives. In severe cases, patients may experience swelling in the throat and wheezing.
- Anaphylaxis – In very rare situations, a patient may go into anaphylactic shock after an allergy shot. This is a life-threatening condition that involves low blood pressure and difficulty breathing. Anyone experiencing symptoms of anaphylaxis should seek out medical care immediately.
How To Know It’s Time To Try Allergy Shots
How can you know if allergy shots are right for you? Patients are a good fit for allergy shots if they:
- Have no fear of needles
- Have a condition that can be treated with allergy shots
- Wish to reduce long-term use of allergy medications
- Have no control over exposure to an allergen (i.e. insect sting allergy)
- Have had little success with controlling symptoms via medications
Allergy shots are not right for every patient. Any patient considering allergy shots should consult with their doctor or allergist to discuss their options.
Allergy Shots FAQ
How Long Does It Take for Allergy Shots To Work?
Patients should begin to see some improvement in symptoms during the build-up stage, though they will not happen immediately. The most significant results typically occur during the second year in the maintenance stage. After the third year, many patients no longer experience significant allergic reactions. Other patients, however, may need ongoing treatment.
How Effective Are Allergy Shots?
Allergy shots can be over 90 percent effective when administered correctly by a medical professional. Results will vary from patient to patient and from one condition to the next.
Do Allergy Shots Lower Your Immune System?
Allergy shots focus on a very particular immune response. While they are designed to ‘lower’ that immune response, they do not affect the overall function and well-being of the immune system.