This study was designed to evaluate the efficacy and safety of sublingual immunotherapy (SLIT) with house-dust mite (HDM) extract in Chinese patients with HDM-induced allergic rhinitis (AR).

Forty-eight patients were eligible for randomization to SLIT with a mixture of Dermatophagoides pteronyssinus and Dermatophagoides farinae extract or placebo for one year. The primary outcome measures for efficacy were the TNSS and the individual nasal symptom score. Secondary endpoints were ACS and MS. AE also was monitored.

The intragroup analysis demonstrated a significant improvement in the active treatment group for individual nasal symptoms and TNSS. However, no improvement was observed in the placebo group of congestion, sneezing, and itching. The active treatment had significant effects on relieving nasal symptoms in adults and children, and no statistical difference was observed between these two subgroups.

The study concluded that SLIT with a mixture of HDM extract significantly relieved allergy symptoms and reduced the need for antiallergic drugs, which indicated the superiority of active treatment over placebo for patients with HDM-induced AR. However, due to the limited sample size, the findings need to be further confirmed.