Study patients
Patients who met the following inclusion criteria were included in the study: (1) a positive allergy test result to Dp and Df by either skin prick test [scored ++ or above (Alutard, ALK-Abellórd, Denmark)] or by PharMacia CAP system for serum sIgE level ≥ 2 (LG Chem, South Korea); (2) a confirmed diagnosis of AR based on the criteria of ‘Allergic Rhinitis and Its Impact on Asthma (ARIA)’12; (3) with ongoing SCIT in one of the selected hospitals before the COVID-19 outbreak; (4) with signed informed consent for participating in this study.
Exclusion criteria were as follows: (1) forced expiratory volume in 1 second (FEV1) < 80%, as predictive value in patients with allergic asthma; (2) pregnant or lactating women; and (3) patients with other contraindications to SCIT.