ABSTRACT
BACKGROUND: Sublingual immunotherapy (SLIT) for perennial allergic rhinitis (AR) has not been extensively studied in preschoolers. We investigated the efficacy and safety of house dust mite (HDM) SLIT-tablet for children aged 1-4 years. METHODS: Children aged 1-4 years with AR were divided into SLIT (n = 22) and control (n = 12) groups based on their guardians' preferences. The SLIT group received a daily dose of 10,000 JAU of HDM SLIT-tablet for 12 months, whereas the control group received symptomatic treatment only. RESULTS: The baseline median age was 41 and 34 months in the SLIT and control groups, respectively, and the median AR symptom score was 4 for both groups. Compared with baseline, the AR symptom score had decreased significantly in the SLIT group after 12 months (score: 3, p = .002), whereas it tended to increase in the control group (score: 6, p = .08). Adverse reactions to SLIT were mild and occurred in eight patients (36%). In the SLIT group, Dermatophagoides (D.) farinae-specific IgE (sIgE) levels increased during the first 6 months and decreased to baseline levels at 12 months. In the control group, D. farinae-sIgE levels had increased significantly at 12 months compared to baseline (p = .01). D. farinae-specific IgG4 and HDM IgE-blocking factor levels were significantly increased at 12 months compared to baseline in the SLIT group only (p < .001). A lower wheezing frequency was seen in the SLIT group (0.3%) compared to the control group (0.7%). CONCLUSION: This pilot study demonstrated the efficacy, safety, and immunomodulatory effects of HDM SLIT-tablet in preschoolers with AR.