Are allergy shots effective?

The process of allergy shots involves the injection of extracts to which you are sensitized. This could include cat, dog, pollen, mold, etc. You are first diagnosed with allergic rhinitis by your symptoms/history and then either blood work (showing positive IgE antibodies) or via skin testing, or both.

After a proper diagnosis, allergy shots could be an option for you. If your symptoms are mild and or well treated with over-the-counter medication, allergy shots may not be worth your time or effort. However, if your symptoms significantly affect your quality of life, your symptoms are very bothersome, your symptoms are not controlled with medication, or if you are sick of taking medication constantly, then allergy shots could be a good option for you. 

But are the shots really effective?

Over 90% of patients who were on allergy shots and got a year of proper maintenance dosing experienced 50-75% improvement in symptoms per one study done². Additionally in this study, after finishing 4-5 years of immunotherapy, about 90% of patients maintained symptom improvement after discontinuing therapy² (Note: evidence is not just from one study as multiple controlled studies have shown effectiveness of immunotherapy for pollen and dust mite allergic rhinitis³) ¹.

Whether and when symptoms come back after stopping shots is hard to know for an individual case. When reaching the end of 3-5 years of allergy shots, options may include stopping cold turkey, spacing out shots (for example to every 6 or 8 weeks) and seeing if symptoms worsen, or just staying on shots. 

Lastly allergy shots have been shown to be effective in helping with asthma and eczema as well^1,4

References

1. Lei DK, Saltoun C. Allergen immunotherapy: definition, indications, and reactions. Allergy Asthma Proc. 2019 Nov 1;40(6):369-371. doi: 10.2500/aap.2019.40.4249. PMID: 31690372.
2. Radtke M, Grammer LC. Subcutaneous administration of allergen vaccines. Clin Allergy Immunol. 2008;21:321-32. PMID: 18828514.
3. Nelson HS. Injection immunotherapy for inhalant allergens. In: Akinson NF Jr, Bochner BS, Burk AW, Busse WW, Holgate ST, Lemanske RF, et al, editors. Middleton’s allergy principles and practice. 8^th ed. Philadelphia: Elsevier/Sauners, 2014; p. 1416-1437.
4. Bogacz-Piaseczyńska A, Bożek A. The Effectiveness of Allergen Immunotherapy in Adult Patients with Atopic Dermatitis Allergic to House Dust Mites. Medicina (Kaunas). 2022 Dec 21;59(1):15. doi: 10.3390/medicina59010015. PMID: 36676639; PMCID: PMC9867076.