From the Guidelines
Allergen immunotherapy, also known as allergy shots, is a two-phase process that involves a build-up phase with injections 1-2 times per week for 3-6 months, followed by a maintenance phase with injections every 2-4 weeks for 3-5 years, as recommended by the most recent guidelines 1.
Process and Protocol
The process starts with an allergist evaluating your symptoms and conducting skin or blood tests to identify specific allergens. Once your personalized extract is prepared, you'll visit the clinic regularly for injections administered by healthcare professionals.
- You must remain in the office for 30 minutes after each injection to monitor for potential reactions.
- Common allergens treated include pollens, dust mites, animal dander, and insect venoms.
- Side effects may include local reactions (redness, swelling) at the injection site or, rarely, systemic reactions like anaphylaxis.
Immunotherapy Mechanism
Immunotherapy works by gradually desensitizing your immune system to allergens, reducing sensitivity over time by promoting tolerance through regulatory T-cells and shifting from allergy-promoting antibodies to blocking antibodies.
- This treatment is particularly beneficial for those with severe allergies, inadequate response to medications, or those seeking long-term relief rather than symptom management.
- The frequency of allergen immunotherapy administration during a conventional build-up phase is generally 1 to 3 injections per week, as stated in previous guidelines 1, but the most recent guideline 1 provides the most up-to-date recommendation.
Key Considerations
Before the administration of the allergy injection, the patient should be evaluated for the presence of asthma or allergy symptom exacerbation, and a patient’s asthma must be stable before the allergen immunotherapy injection is administered 1.
- The starting dose for build-up is usually a 1,000-fold or 10,000-fold dilution of the maintenance concentrate, although a lower starting dose might be advisable for highly sensitive patients 1.
- Allergen immunotherapy has immunomodulation activity and modifies the natural history of atopic allergy, but it also poses the risk of side-effects, including local and systemic reactions 1.
From the Research
Allergy Shot Process and Protocol
The process and protocol for receiving allergy shots, also known as allergen immunotherapy, involve the administration of increasing amounts of specific allergens to which the patient has type I immediate hypersensitivity 2. This can be done through subcutaneous injections in a physician's office or sublingually by the patient at home.
Indications for Allergen Immunotherapy
Allergen immunotherapy is indicated for the treatment of:
- Allergic rhinitis
- Allergic conjunctivitis
- Allergic asthma
- Hymenoptera hypersensitivity It is considered when:
- Symptom control is inadequate despite pharmacotherapy and avoidance measures
- The patient wants to reduce morbidity from allergic rhinitis and/or asthma, or reduce the risk of anaphylaxis from a future insect sting
- The patient experiences undesirable adverse effects from pharmacotherapy
- Avoidance is not possible 2
Administration Routes
Allergen immunotherapy can be administered through two main routes:
- Subcutaneous injections in a physician's office
- Sublingual administration by the patient at home 2, 3 Both routes have been shown to be effective in modifying the underlying cause of the disease, with long-term clinical benefits after treatment cessation 3
Efficacy and Safety
Studies have shown that allergen immunotherapy significantly reduces symptoms and medication requirements in allergic rhinitis 4, 5. Sublingual immunotherapy (SLIT) has been found to be a safe treatment with significant reductions in symptoms and medication requirements 4, 5. The long-term efficacy of both sublingual and subcutaneous routes has been demonstrated, with sustained clinical benefits after treatment cessation 3
Key Considerations
- Specific immunoglobulin E (IgE) antibodies for appropriate allergens must be documented before starting immunotherapy 2
- The total dose of allergen administered may be important, but insufficient data is available to analyze this factor 4, 5
- Further research is required to optimize allergen dosage and patient selection 5