The impact of adverse reactions on adherence to sublingual immunotherapy for Japanese cedar pollinosis and house dust mite allergy in Japan

Background: Allergen immunotherapy is the only treatment that can achieve remission for allergic diseases. Aims/Objectives: To investigate the three-year adherence to sublingual immunotherapy for Japanese cedar pollinosis and house dust mite allergy at a clinic in Japan and identify factors that influence adherence and severe adverse reactions. Material and Methods: In total, 174 patients aged 12 years or older who started sublingual immunotherapy for Japanese cedar pollinosis (n = 72), house dust mite allergy (n = 55), or both (n = 47) between May 2017 and June 2018. Patient age, sex, type of pharmacotherapy used, adverse reactions, blood test results, and duration of continuous treatment were investigated. Results: The three-year treatment continuation rate was 40.8%. Adverse reaction rates were 12.6% for cedar pollinosis and 40.2% for house dust mite allergy. Patients with dose reductions due to severe reactions had lower first-year continuation rates. In the MITICURE (R) group, patients with severe reactions had significantly higher serum total IgE levels. Severe reactions were more common in MITICURE (R) patients with seven or more positive antigen types. Conclusions and Significance: Severe adverse reactions reduced early adherence.