Sublingual Immunotherapy - Tongue's Immune Tune-up
- Mechanism: Allergen under tongue → oral dendritic cells → T-regulatory (Treg) cell induction → immune tolerance. Shifts Th2 to Th1 response.
- Indications: Allergic rhinitis/conjunctivitis (House Dust Mite, pollens), mild controlled asthma.
- Administration: Daily self-administration (tablets/drops). Held sublingually for 1-2 min before swallowing.
- Duration: Typically 3-5 years for sustained effect.
- Safety:
- Common: Local oropharyngeal itching, swelling (usually transient).
- Rare: Systemic reactions (anaphylaxis very rare, less than SCIT).
- Advantages: Home-based, ↑convenience, generally ↑safety profile vs. SCIT.
- Contraindications: Severe uncontrolled asthma, active eosinophilic esophagitis (EoE).
⭐ SLIT primarily induces allergen-specific IgG4 & IgA, and promotes T-regulatory (Treg) cell development, leading to immune tolerance.
Sublingual Immunotherapy - Drop Candidate Check
- Eligibility Criteria:
- Age: >5 years (product-dependent).
- IgE-mediated: Allergic rhinitis/conjunctivitis, mild/moderate controlled asthma.
- Sensitization: Positive SPT/sIgE to specific allergen.
- Key Contraindications (CI):
- Absolute:
- Severe/uncontrolled asthma (FEV1 <70%).
- Active autoimmune disease.
- Beta-blocker therapy.
- Eosinophilic Esophagitis (EoE).
- Relative:
- Poor adherence.
- Significant oral lesions/inflammation.
- Pregnancy (initiation CI; continuation case-by-case).
- Absolute:
- First Dose Administration:
- First dose in clinic.
- 30-min observation post-dose.
- Monitor local/systemic reactions (e.g., oral pruritus).
⭐ First dose of SLIT must be given under medical supervision with a 30-minute observation period to monitor for adverse reactions.
Sublingual Immunotherapy - Dose, Drops, Drama
- Mechanism: Targets mucosal dendritic cells → Treg induction, ↓Th2 response, ↑IgG4.
- Allergens: Common: House Dust Mite (HDM), grass/tree/ragweed pollens.
- Indications: Allergic rhinitis ± conjunctivitis, mild-moderate controlled allergic asthma.
- Contraindications: Severe/uncontrolled asthma (FEV1 < 70% predicted), concurrent beta-blocker use, active eosinophilic esophagitis (EoE), pregnancy (for initiation).
- Administration (Drops/Tablets):
- Held under tongue for 1-2 minutes, then swallowed.
- Daily dosing.
- Typical duration: 3-5 years for sustained effect.
- Adverse Effects (Drama):
- Local (common): Oral pruritus, throat irritation, GI upset. Usually mild, transient.
- Systemic (rare): Urticaria, angioedema; anaphylaxis very rare.
- First dose often administered under medical supervision.

⭐ SLIT offers a significantly better safety profile compared to SCIT (Subcutaneous Immunotherapy), with a much lower risk of systemic anaphylactic reactions, making it suitable for home administration after the first dose for many patients.
Sublingual Immunotherapy - Allergy Rivals Rumble
- Mechanism: Sublingual allergen delivery → oral Langerhans & dendritic cells → Treg induction → immune tolerance. 📌 SLIT: Safe, Lingual, In-home Treatment.
- Indications:
- Allergic rhinitis/conjunctivitis (specific pollens like grass/ragweed, HDM).
- Mild, controlled allergic asthma.
- Advantages (vs. SCIT):
- ↑ Safety profile (significantly ↓ anaphylaxis vs SCIT).
- Home administration.
- Non-invasive (oral).
- Disadvantages:
- Local AEs: oral/pharyngeal itching, swelling, GI upset (usually mild, transient).
- Daily dosing.
- Duration: 3-5 years for sustained effect.
- Contraindications: Key CIs: Severe uncontrolled asthma, active autoimmune disease, prior EoE with SLIT.
⭐ First dose of SLIT (tablets for grass, ragweed, HDM) typically administered under medical supervision to manage potential initial reactions.
High‑Yield Points - ⚡ Biggest Takeaways
- SLIT offers a safer profile than SCIT, with a significantly lower anaphylaxis risk.
- Effective for allergic rhinitis and asthma, particularly with mono-sensitization to aeroallergens like HDM or pollens.
- First dose may be medically supervised; subsequent doses are typically self-administered daily at home.
- Most common adverse effects are local oropharyngeal symptoms (itching, mild swelling); severe systemic reactions are rare.
- Induces allergen-specific tolerance via T-regulatory cells (Tregs) and IgG4 blocking antibodies.
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