Clinical efficacy and safety of coseasonal initiation of Artemisia annua sublingual immunotherapy on patients with Artemisia-induced rhinoconjunctivitis

Patients with seasonal allergic rhinoconjunctivitis (SARC) might seek evaluation and treatment when symptoms appear during the pollen season. It is unclear whether coseasonal-initiated sublingual immunotherapy (SLIT) would be effective and safe for SARC. This study aims to identify the feasibility of initiating Artemisia annua SLIT during the pollen season.Sixty patients with Artemisia-induced SARC were equally recruited into the SLIT and control groups during the pollen season in 2021. The SLIT group was treated with standardized Artemisia annua SLIT drops using a modified dosing schedule combined with pharmacotherapy, while the control group only received pharmacotherapy. Diary cards for clinical symptoms, rescue medication use, and adverse events (AEs) were recorded during the pollen seasons. Objective measures, including average daily combined scores of medication and rhinoconjunctivitis symptoms (CSMRS), total rhinoconjunctivitis symptom score (TRSS), total medication score (TMS), and the score of visual analog scale (VAS) were calculated to evaluate the efficacy of SLIT. Safety was assessed through the occurrence and severity of AEs.In total, 80.0 % (24/30) patients in the SLIT group and 86.67 % (26/30) patients in the control group completed the study. The severity of SARC, which was assessed by objective measures including CSMRS, TRSS, TMS, and VAS of the SLIT group and the control group, was generally at the same level during the 2021 pollen season, except for the medical consumption, which the score of TMS was slightly higher in the SLIT group. After one year of treatment, the scores of CSMRS, TRSS, and VAS in the SLIT group were significantly improved compared with the control group (all P < 0.001), and the difference in the TMS between the two groups disappeared (P > 0.05). Moreover, clinical improvement of the four objective measures was also observed in the SLIT group compared with the baseline value (P < 0.001). Overall, 9/24 patients in the SLIT group experienced mild local AEs, and two patients experienced mild systemic AEs during the SLIT period.This controlled preliminary study identified that coseasonal-initiated Artemisia annua SLIT treatment for one year was generally safe and effective in improving the symptoms of SARC patients induced by Artemisia annua pollen.