Sublingual Immunotherapy for Allergies
Sublingual immunotherapy (SLIT) is an effective and safe treatment for allergic rhinitis and rhinoconjunctivitis that you should offer to patients with moderate to severe allergic symptoms who have inadequate response to antihistamines and intranasal corticosteroids. 1
Patient Selection Criteria
Select patients who meet these specific requirements:
- Confirmed IgE sensitization to the relevant allergen via skin prick testing and serum-specific IgE 1
- Moderate to severe symptoms documented in the previous year with allergen exposure 2, 1
- Inadequate response to optimal pharmacologic treatment with antihistamines and intranasal corticosteroids 1
- Monosensitized patients are ideal, though polysensitized patients can also benefit 1
Dosing and Administration Protocol
Start directly with the maintenance dose—no updosing phase is required:
- Maintenance dose: approximately 5 mg of major allergen per day (roughly 30 times the monthly subcutaneous immunotherapy dose) 2, 1, 3
- Once-daily administration is the standard regimen 2
- Begin at least 8 weeks before pollen season for seasonal allergens using a pre-co-seasonal regimen 2, 1, 3
- Continue for at least 3 years to achieve disease modification and sustained tolerance after treatment cessation 4
The traditional updosing phase is unnecessary, and starting with the maintenance dose does not increase adverse events 2, 3
Safety Profile and Adverse Event Management
SLIT demonstrates superior safety compared to subcutaneous immunotherapy:
- No SLIT-related fatalities have been reported, and anaphylaxis is extremely rare (only 3 case reports in the literature) 1, 5, 3
- Local oral reactions occur in 0-70% of patients but typically remit within 1-2 weeks 1, 5
- The most common reactions are nasal symptoms (50.5%), mouth/throat symptoms (18.1%), and eye symptoms (16.5%) 2, 3
For uncomfortable local reactions: Consider a 2- to 4-week course of antihistamine pretreatment to improve tolerability 6
For severe swelling or systemic reactions: Immediate physician evaluation is required to decide on continuation versus alternative routes of administration 6
Clinical Efficacy Expectations
Approximately 80% of randomized controlled trials demonstrate positive results for SLIT 2, 1
- Meta-analyses show significant reductions in both symptoms and medication requirements compared to placebo 1
- Proven efficacy for grass pollen, tree pollen, ragweed, dust mite, and parietaria allergens 1
- Important caveat: About 35% of trials do not demonstrate efficacy in the first year, so ongoing assessment and potential dose adjustment may be needed 5, 3
Multiple Allergen Treatment
Single allergen SLIT is preferred until more definitive data on multiple allergen regimens become available 2
For patients requiring treatment of multiple allergens, sequential administration of different SLIT tablets can be considered based on tolerability and patient preference, though this remains somewhat experimental 6
Guideline Recognition
The World Health Organization recognizes SLIT as an effective treatment for allergic rhinitis and rhinoconjunctivitis 1
The American Academy of Otolaryngology-Head and Neck Surgery recommends SLIT for patients with inadequate response to pharmacologic therapy, with moderate-quality evidence 1
The ARIA 2010 guidelines provide conditional recommendations with moderate-quality evidence for both adults and children with pollen-induced allergic rhinitis 1