Objective  To explore the clinical efficacy and influencing factors of children receiving mite-specific subcutaneous immunotherapy (SCIT).

  Methods  We retrospectively analyzed the data of children who had received mite SCIT for 3 years at the Desensitization Center of our hospital. We used the daily medication score (DMS) to evaluate the medication use status (the higher the score, the higher the amount of medications given and the less satisfactorily was the primary disease controlled) and we used the visual analogue scale (VAS) to evaluate clinical symptoms (the higher the score, the more severe the symptoms). Evaluation was performed after the first SCIT treatment and after treatment was given for 3 months, 4 months, 12 months, and 3 years. According to whether medication for the primary disease was stopped after 3 years, the patients were divided into two groups, the discontinued medication group (discontinued group) and the continued medication group (continued group). The general data, DMS, VAS and the decline rate of the two groups were compared, and logistic regression was performed to analyze the influencing factors of the outcome.

  Results  A total of 711 children were enrolled in the study, with an average age of 8.38 years at the time of the first visit to the hospital. There were 442 males and 269 females. Skin prick test showed that 445 cases only had mite allergy, and 266 cases had mite allergy combined with other allergies. 360 cases have discontinued the medication for the primary disease after 3 years, and 351 cases had relieved symptoms, but still needed to continue with the medication. At the beginning of SCIT treatment, the DMS and VAS of the discontinued group were lower than those of the continued group (P<0.05). Evaluations from 3 months to 3 years showed that both DMS and VAS continued to decrease compared with those from the beginning, and the decline rate of DMS and VAS of the discontinued group was higher than that of the continued group after 3 years of SCIT (P<0.05). After 3 months of SCIT, the positive rates of nasal and ocular symptoms in the discontinued group were lower than those in the continued group (P<0.05). After 3 years of SCIT, the positive rates of nasal, ocular, and chest symptoms in the discontinued group were lower than those in the continued group (P<0.05). Univariate analysis combined with multivariate logistic regression showed that initial DMS>4 points and initial VAS>3.5 points were protective factors for the discontinuation of the medication for the primary disease at the end of 3 years of SCIT, while the female sex and DMS reduction rate after 12 months of treatment>50% were risk factors for discontinuation.

  Conclusions  Mite SCIT can help relieve clinical symptoms and reduce the use of medication for symptomatic treatment. Symptoms can be improved after 3 months of SCIT, with the fastest improvement shown in nasal and eye symptoms. It is not recommended to discontinue the medication for the primary disease for too much after 1 year of treatment.