Abstract: Objective  To observe the  clinical efficacy and safety of long-term sublingual immunotherapy with dermatophagoides farinae drops in ch
ildren with bronchial asthma  and to provide a safe and effective method to treat bronchial asth
ma in children.Methods  A two-year randomized and parallel-controlled study was conducted in
128 children (aged 4-14 years) with mild to moderate asthma symptoms.The patients
were randomly assigned to treatment group and control group(n=64).The patients in treatment group were treated with sublingual immunotherapy (SLIT) with dermatophagoides farinae drops.The patients in control group were treated according the manufacturer's instructions.The clinical efficacy was evaluated by monthly follow-up visits.After treatment for 6 months，1 year and  2 years using
 dermatophagoides farinae drops,the asthma symptom scores and PEF%  were evaluated.
Results Of the 128 children,5 cases dropped out before the study completion.After 6 months,1 year and  2 years of treatment,the allergic asthma symptom
 scores of the patients  in treatment group were significantly decreased compared with control group
 (P<0.05).After 6 months,1 year and 2 years of treatment,the PEF% of the patients in treatment group were
singnificantly increased compared with control group (P<0.05).There were no severe adverse events during the course of immunotherapy,except for mild reactions.
Conclusion Long-term  sublingual immunotherapy with dermatophagoides farinae drops can signi
ficantly improve symptoms and lung function in children with  asthma,and lower the incidence of adverse reactions,so it is effective and safe in the treatment
of children with bronchial asthma.

Key words: bronchial asthma, dermatophagoides farinae drops, specific immunotherapy, sublingual administration