To evaluate the efficacy and safety of the sublingual immunotherapy with Dermatophagoides fannae drops on children with allergic rhinitis of different age groups （4 - 5 years old group and 11 - 12 years old group）.

Sixty-two children aged 4 -5 years, and 71 children aged 11 - 12 years, who suffered from dust mite induced allergic rhinitis, was randomly divided into the sublingual immunotherapy （SLIT） ＋ drug group and drug group. SLIT ＋ drug group was treated with a standardized sublingual immunotherapy drops of Dermatophagoides fannae and combined with symptomatic therapy, drug group was treated with mometasone furoate nasal spray and desloratadine tablets as symptomatic treatment. These children were followed up for 2 years with one visit in every 3 months, then visited at the end of the study and 2-years after the treatment ended. Symptom scores and medication scores were recorded at each visit. Comprehensive evaluation of symptoms, medication, and patients＇ degree of satisfaction were used.

Two years after SLIT finished, symptom scores （SLIT ＋ drug group ： 1.13 ± 1.05 ; drug group： 4.68 ± 3.09）, medication scores （SLIT ＋ drug group：0.07 ± 0.04 ; drug group：0.36 ± 0.25） of SLIT ＋ drug group were significantly lower than those in drug group （t value were -8.43, -8.87, respectively, all P < 0.01）. Also, the subjective assessment of patients＇ symptoms, medication, and treatment satisfaction in SLIT ＋ drug group was significantly lower than those in drug group. Subjective assessment symptoms, medication, and treatment satisfaction in age group 4 - 5 was the same as in age group 11 - 12. After SLIT ended for 2 years, subjective assessment and treatment satisfaction in age 11 - 12group was better than those in age 4 -5 group in medication score.

SLIT demonstrated clinical improvement in children of different ages during 2 years treatment. Two years after withdrawal, the symptom scores, medication score and subjective satisfaction in 11 years old group are better than those in 4 - 5 years old group.

Rhinitis, allergic, perennial;  Desensitization immunologic ;  Administration,Sublingual ;  Treatment outcome