Longitudinal SNOT-22 Symptom Changes With Sublingual Immunotherapy (SLIT)

Despite widespread use of nasal corticosteroids and oral antihistamines, many patients with allergic rhinitis (AR) have persistent nasal congestion/obstruction and rhinorrhea with associated sleep disturbance and daytime fatigue. Sublingual immunotherapy (SLIT) is associated with reducing symptom burden and medication use. This study aims to evaluate time to clinical benefit and magnitude of first-year benefit after SLIT initiation.

Adult AR patients confirmed by skin or IgE testing who initiated allergen-directed SLIT were included. Sinonasal Outcome Test-22 (SNOT-22) and Rhinitis Control Assessment Test (RCAT) surveys were recorded at baseline, 1-6, and 6-12 months after SLIT. Longitudinal changes were assessed using repeated measures analysis of variance and minimal clinically important difference (MCID) thresholds. Exploratory analysis at 3 months was performed for a subset of patients.

A total of 43 SLIT patients (mean age 42.1 ± 12.0 years; 40% female) were included and demonstrated significant reductions in total SNOT-22 scores at 1-6 months (-12.1 points; -35%) and 6-12 months (-12.5 points; -36%) (p < 0.01 from baseline). Nasal, sleep, and function SNOT-22 subscores each improved significantly from baseline, whereas the ear/facial subscore did not. MCID for total SNOT-22 was achieved by 54.3% of patients at 1-6 months. RCAT scores improved significantly at 1-6 months and 6-12 months. The proportion of patients with normal SNOT-22 score (≤ 8) increased from 4.7% at baseline to 24.1% at 6-12 months.

SLIT was associated with symptom improvement within the first 6 months of therapy based on SNOT-22 and RCAT scores. Symptom score improvements persisted to 12 months, and findings support evidence of early nasal, sleep, and function symptom alleviation with SLIT.