What Are Allergy Shots For? Conditions Treated and Not Treated

Venom immunotherapy is the most effective and near-curative application of allergy shots. Research summarized by Golden et al. (JACI 2017) shows that 80–95% of patients who complete a full course of venom immunotherapy are protected from anaphylaxis if stung again. This is compared to a 25–60% risk of systemic reaction with each sting in untreated venom-allergic patients. The treatment uses standardized FDA-approved extracts of honeybee, yellow jacket, white-faced hornet, yellow hornet, or wasp venom — the specific venom targeted by your shots depends on your skin or blood test results. Venom immunotherapy is generally recommended for a minimum of 5 years, after which many patients retain protection indefinitely.

Standard allergy shots (SCIT) are not used for food allergies. Subcutaneous injection of food allergen extracts has an unacceptable reaction rate — the systemic delivery route creates too high a risk of anaphylaxis with food proteins. Food allergy immunotherapy uses two alternative approaches: oral immunotherapy (OIT), where gradually increasing amounts of the food allergen are consumed under medical supervision, and sublingual food immunotherapy (SLIT-food), where small amounts are held under the tongue. These protocols are specific to food allergens and are not interchangeable with environmental allergen immunotherapy. Palforzia (AR101) is the only FDA-approved food OIT product, for peanut allergy in patients aged 4–17. If you have both food and environmental allergies, your allergist can address them with the appropriate treatment modality for each.

Allergy shots are effective for allergic asthma — a Cochrane review by Abramson et al. (2010) found a standardized mean difference of -0.59 in asthma symptom scores — but require careful patient selection. AAAAI and GINA 2023 guidelines specify that SCIT should only be initiated in patients with stable, well-controlled asthma with FEV1 greater than 70% of predicted. Patients with poorly controlled or severe asthma are at significantly higher risk of systemic reactions during allergy shots. Before starting immunotherapy, your allergist will assess your asthma control with spirometry or peak flow testing. If your asthma is not well-controlled, optimizing your asthma medications first is the appropriate approach. Once stabilized, many asthma patients benefit substantially from immunotherapy.

Yes — one of the most compelling benefits of allergen immunotherapy is its disease-modifying effect on new sensitization. The Preventive Allergy Treatment (PAT) study by Jacobsen et al. demonstrated that monosensitized children (allergic to one pollen) who received immunotherapy were significantly less likely to develop new allergen sensitizations over a 10-year follow-up period compared to untreated controls. The same study showed reduced progression from allergic rhinitis to asthma in treated children. This preventive benefit is strongest when treatment begins early — in children with single sensitization before multiple sensitizations develop. For adults who are already polysensitized, the primary benefit is symptom reduction rather than sensitization prevention.

The evidence for using allergy shots in atopic dermatitis (eczema) is limited and insufficient to support routine use. A Cochrane review by Tam et al. (2016) found insufficient evidence to recommend SCIT as a standard treatment for eczema. Some small studies show improvement, particularly in patients with confirmed dust mite sensitization and dust mite-driven eczema flares, but the research base is much weaker than for rhinitis or venom allergy. Current AAAAI and EAACI guidelines do not list atopic dermatitis as a primary indication for allergy shots. Patients with eczema who also have confirmed IgE-mediated environmental allergies may receive allergy shots for their rhinitis or asthma components, with any eczema improvement considered a potential secondary benefit rather than the primary treatment goal.

Allergy shots do not treat food allergies, drug allergies, latex allergy (latex extracts were withdrawn from the US market due to anaphylaxis risk), contact dermatitis (which is a T-cell-mediated reaction, not IgE-mediated), and most chronic urticaria (except cases driven by insect venom allergy). They are also not indicated for non-IgE-mediated reactions, irritant-triggered conditions, or allergies to substances for which no standardized or validated extract exists. Patients with only food allergies should explore OIT or SLIT-food protocols with a food allergy specialist. Patients with drug allergies should discuss desensitization protocols (rapid IV or oral desensitization) with their allergist, which are entirely distinct from allergen immunotherapy injections.