Allergen-specific immunotherapy (AIT) is considered to be the only etiology-based treatment available for patients with immunoglobulin E (IgE)-mediated allergic diseases such as allergic rhinitis (AR) [1]. Existing research has consistently demonstrated that sublingual immunotherapy (SLIT) can achieve short-term benefits in AR patients by improving nasal symptoms, reducing medication needs and improving quality of life [2]. Displaying a disease-modifying effect, SLIT also induces long-term tolerance that might persist for several years after cessation of treatment, as further demonstrated by the prevention of disease progression and new allergic sensitizations [3]. Different courses of SLIT have been shown to significantly improve clinical outcomes of patients with house dust mite (HDM)-induced AR, and 3 years of SLIT might be more effective than a 1- or 2-year course [4]. However, the long-term benefits of HDM SLIT were rarely reported and limited studies on the relationship between SLIT duration and long-term efficacy have been performed.

Total symptom score, total medication score, individual symptom scores, visual analogue scale (VAS) and validated questionnaires assessing Health-Related Quality of Life (HRQL) have been recommended as possible endpoints in SLIT studies for efficacy evaluation [5]. The Mini Rhinoconjunctivitis Quality of Life Questionnaire (MiniRQLQ) is a convenient and effective tool for assessing treatment outcomes [6]. Despite its potential, the application of MiniRQLQ in SLIT is rare, and further research is needed to establish the correlation between MiniRQLQ and traditional indicators. Furthermore, disease severity and corticosteroid use are also areas of concern for clinicians. In this study, we compared the short-term and long-term efficacy of HDM-induced AR patients receiving SLIT of different durations in multiple clinical outcomes, aiming to explore the relationship between SLIT duration and effectiveness.