[Efficacy of sublingual immunotherapy with Dermatophagoides farinae drops in preschool and school-age children with allergic asthma and allergic rhinitis].

OBJECTIVE: To evaluate the efficacy of specific sublingual immunotherapy (SLIT) with Dermatophagoides farinae drops on children with allergic asthma and allergic rhinitis of the preschool and school-age groups of children and adolescents.

METHOD: This study analyzed the efficacy of SLIT in 122 children (aged 3-14 yr) with house dust mites-induced allergic asthma and allergic rhinitis. According to the age, patients were defined as the preschool group ( ≤ 6 years old, n = 59) and school-age group (> 6 years old, n = 63). All children were treated with Dermatophagoides farinae drops for at least 2 years. Clinical observation and follow-up study were conducted during the treatment. Before and after SLIT for half a year, 1 year and 2 years, asthma symptom scores (day and night), rhinitis symptom scores and medication scores were evaluated. The adverse events were assessed during the study.

RESULT: After SLIT for half a year, 1 year and 2 years, there were no significant differences between the preschool group (0.3 ± 0.5,0.0 ± 0.1,0.0 ± 0.0) and school-age group (0.3 ± 0.4,0.0 ± 0.1,0.0 ± 0.0) in day scores of asthma (Z value was -1.687, -0.613,0.000, all P > 0.05). There were no significant differences between the preschool group (0.2 ± 0.5,0.1 ± 0.3,0.0 ± 0.0) and school-age group (0.2 ± 0.4,0.1 ± 0.3, 0.0 ± 0.0) in night scores of asthma (Z value was -0.496, -0.486,0.000, all P > 0.05). There was no significant differences between the preschool group (1.4 ± 0.9,0.4 ± 0.5,0.1 ± 0.3) and school-age group (1.3 ± 0.9,0.5 ± 0.6,0.2 ± 0.4) in symptom scores of allergic rhinitis (Z value was -0.394, -1.166, -1.075, all P > 0.05). There were no significant differences between the preschool group (1.6 ± 0.8,0.0 ± 0.0,0.0 ± 0.0) and school-age group (1.7 ± 0.7,0.0 ± 0.0,0.0 ± 0.0) in medication scores of allergic rhinitis (Z value was -0.655,0.000,0.000, all P > 0.05). After SLIT for 2 years, most children in the preschool and school-age groups were no longer using asthma controlling medication, with no significant difference between the two groups (Z value was 0.000, P > 0.05). The overall incidence of adverse reactions was only 7%, and there was no significant difference in the incidence of adverse reactions between the two groups (χ(2) = 0.000, P > 0.05). The local adverse events were mild gastrointestinal discomfort and rash, a majority of local adverse events in the preschool group were diarrhea. No severe adverse events happened in the treatment.

CONCLUSION: SLIT with Dermatophagoides farinae drops is safe and effective in children with allergic asthma and allergic rhinitis of the preschool and school-age groups of children and adolescents, which provides evidences for early SLIT intervention of the disease.