From the Guidelines
Subcutaneous immunotherapy (SCIT) is generally more effective than sublingual immunotherapy (SLIT) for treating allergies, but SLIT offers better safety and convenience. When considering the efficacy of injection vs subbing allergy immunotherapy, it's essential to weigh the benefits and risks of each approach. SCIT involves regular injections at a doctor's office, typically weekly during the build-up phase, then monthly for maintenance, continuing for 3-5 years 1. This method is more effective for multiple allergens and shows stronger, more durable responses for conditions like allergic rhinitis, allergic asthma, and insect venom allergies. On the other hand, SLIT involves daily self-administration of tablets or drops under the tongue at home, also typically for 3-5 years, and has a better safety profile with minimal risk of severe reactions 1.
Some key points to consider when deciding between SCIT and SLIT include:
- Efficacy: SCIT is generally more effective, but SLIT can still provide significant symptom relief
- Safety: SLIT has a better safety profile, with minimal risk of severe reactions
- Convenience: SLIT is more convenient, as it can be self-administered at home, while SCIT requires regular office visits
- Patient preference: The choice between SCIT and SLIT should be individualized based on patient preference, compliance ability, and safety considerations
It's also important to note that the mechanism for both SCIT and SLIT involves gradually exposing the immune system to increasing amounts of allergens, shifting from a Th2 allergic response to a Th1 response and inducing regulatory T-cells that suppress allergic reactions 1. Ultimately, the decision between SCIT and SLIT should be based on a thorough evaluation of the patient's specific needs and circumstances.
From the Research
Efficacy of Injection vs Subbing Allergy Immunotherapy
- The efficacy of subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) has been compared in several studies, with both methods showing effectiveness in treating allergic rhinitis 2, 3, 4.
- SCIT has been the gold standard, while SLIT has emerged as a safe and effective alternative, with similar efficacy in respiratory allergy 2, 4.
- Studies have demonstrated reductions in symptoms and use of rescue medication in patients with seasonal and perennial allergic rhinitis treated with both SCIT and SLIT 2, 3.
Safety Considerations
- Systemic reactions to allergen injections are rare, but near-fatal and fatal anaphylactic reactions can occur, particularly in patients with asthma 5.
- Patients with severe and uncontrolled asthma are at greater risk for more severe reactions, and treating allergists should institute best clinical practices to prevent and manage severe systemic reactions to SCIT 5.
- SLIT is considered a safer alternative to SCIT, with a lower risk of systemic reactions 4.
Dosing Considerations
- Proper dosing is important for both SCIT and SLIT, with effective doses falling within a narrow range 6.
- Less-effective doses may sacrifice most or all of the potential efficacy of the treatment, and analysis of available data suggests that effective doses are relatively narrow 6.
- The optimal dose for sublingual allergy immunotherapy has been determined for approved tablets, but not for liquid extracts except for ragweed 6.
Comparison of SCIT and SLIT
- The choice between SCIT and SLIT may be determined by local availability of products, personal preference, and individual patient needs 2, 4.
- Both SCIT and SLIT have economic advantages over symptomatic drugs, providing long-term benefits and improving quality of life for patients with allergic rhinitis 3, 4.