Immunotherapy is a long-term allergy treatment that takes upwards of five years to complete. When you settle in for a lengthy treatment, knowing what to expect at each stage can help you stay motivated to complete the entire process.
First Six Months to One Year
Immunotherapy begins with a build-up phase that lasts about six months. During the build-up phase, you’ll receive gradually increasing doses of the allergen you’re treating to increase your tolerance of the substance.
Because the doses increase, you’re more likely to experience allergy symptoms during the build-up phase. These symptoms may include, but are not limited to, sneezing, itchy skin or hives and congestion. You can manage mild symptoms with allergy medication. Serious symptoms are rare with immunotherapy, but they can happen. If you develop wheezing, facial swelling or other symptoms of anaphylaxis at home, you should seek emergency medical attention and will likely require an epinephrine injection.
The severity of your allergies and the treatment option you choose (shots vs. drops) will determine whether we have you take your doses in-office or at home.
Many patients notice a slight symptom reduction during the first three to four months[1] for drops and between the first six months to one year for shots.[2]
18 Months to Five Years
More noticeable relief will occur in the second and third year marks. Your symptoms will gradually reduce until they reach their low point. Improvement varies among patients, but a few studies have shown promising results with consistent treatment.
A 2023 analysis of the REACT study found that immunotherapy patients who remained consistent with their treatment showed a greater symptom reduction than their counterparts who did not stick with their treatment.[3]
The results of a 2025 pediatric study supported the 2023 analysis. The study found that children undergoing immunotherapy saw a greater reduction in allergy and asthma symptoms and medication use.[4]
Immunotherapy is a commitment, but being able to breathe freely at Huntington Park makes it well worth the wait. Contact us at Hampton Roads ENT ~ Allergy to schedule a consultation with one of our specialists.
[1] Johns Hopkins Medicine. (2024, July 13). Could allergy drops be the key to allergy relief? Johns Hopkins Medicine. https://www.hopkinsmedicine.org/health/conditions-and-diseases/seasonal-allergies/could-allergy-drops-be-the-key-to-allergy-relief
[2] Cleveland Clinic medical professional. (2023z). Allergy shots. Cleveland Clinic. https://my.clevelandclinic.org/health/treatments/25194-allergy-shots
[3] Contoli, M., Porsbjerg, C., Buchs, S., et al. (2023). Real-world, long-term effectiveness of allergy immunotherapy in allergic rhinitis: Subgroup analyses of the REACT study. Journal of Allergy and Clinical Immunology, 152, 445–452.e4.
[4] Woehlk, C., Stranzl, T., Contoli, M., Freemantle, N., Slaettanes, A. K., Larsen, J. R., Porsbjerg, C., & Fritzsching, B. (2025). Long-Term, Real-World Effectiveness of Allergen Immunotherapy in Children and Adolescents With Allergic Rhinitis and Asthma. Allergy, 80(12), 3331–3341. https://doi.org/10.1111/all.70085