Observation and analysis of systemic reactions to house dust mite subcutaneous immunotherapy in 362 patients with allergic rhinitis

Abstract

Objective: To investigate the frequency and severity of systemic reactions (SRs) to standardized house dust mite subcutaneous immunotherapy (SCIT) in patients with perennial allergic rhinitis (AR), and to analyze the clinical risk factors. Methods: The clinical data of 362 patients including 209 males and 153 females, aged from 5 to 55 years old receiving SCIT at the Department of Otorhinolaryngology, the Third People's Hospital of Changzhou were collected from May 2014 to July 2017. The SRs were classified as early-onset and delayed-onset, and 4 grades (grade Ⅰ to Ⅳ) to assess severity. The records of SRs were retrospectively analyzed, including the numbers/frequencies, symptoms and signs, onset of reaction and treatment. And the relationships between SRs and patient's age, gender, allergen injection dose, accompanied allergic diseases were explored. All the statistical analyses were conducted using SPSS 19.0. Results: There were 57 cases (15.75%) of SRs in 362 patients. All the patients received a total of 12 308 injections and 111 SRs (0.90%) were observed. Among them, 31 (27.93%) were early-onset reactions and 80 (72.07%) were delayed-onset reactions; most of the SRs were grade Ⅰ reactions (n=83, 74.78%), followed by grade Ⅱ (n=25, 22.52%), grade Ⅲ (n=3, 2.70%), and no fatal reactions occurred. The incidence of SRs in patients>14 years old was higher than that in patients ≤14 years old according to the number of cases and injections (35.14% vs 13.54%, 2.34% vs 0.76%, χ(2) value was 11.679, 28.162, respectively, all P<0.05), but no significant differences of SRs were observed in gender (18.66% vs 11.76%, 5.98% vs 5.62%, χ(2) value was 3.166, 0.095, respectively, all P>0.05). Fifteen SRs (13.51%) occurred during the build-up phase and 96 (86.49%) during the maintenance phases. SRs could occur in lots of dose phases, and 95 (85.59%) were distributed at high concentrations more than 40 000 SQ-U. The incidence of SRs in patients with multiple allergic diseases was significantly higher than that in patients with AR alone, with asthma or atopic dermatitis (30.67% vs 11.85%, χ(2)=15.875, P<0.001). Meanwhile, the incidence of SRs in patients with pure AR was also significantly lower than that in patients with other allergic diseases (5.26% vs 20.56%, χ(2)=13.783, P<0.001). Conclusions: The incidence of SRs is less than 1% according to the injection times, the severity of SRs is mostly slight, and the safety and tolerance are good during standardized house dust mite SCIT in perennial AR patients. Delayed-onset SRs are more common. The incidence of SRs is significantly correlated with age, high dose of allergen vaccine injection, and concomitant other allergic diseases (asthma, atopic dermatitis, etc).