Safety of semi-depot house dust mite allergen extract in children and adolescents with allergic rhinitis and asthma.

Multicenter study to investigate the safety of mite extract product Novo-Helisen Depot, Strengths 1 to 3 (NHD3), as subcutaneous immunotherapy (SCIT), in Chinese children and adolescents with allergic rhinitis (AR) and allergic asthma (AA). We evaluated SCIT-related adverse events (AEs) during NHD3 14-week initial therapy in children (5-11 years) and adolescents (12-17 years) with perennial symptomatic AR and AA. Among 3600 injections in 250 patients, 361/3600 (10.0%) injections caused SCIT-related AEs in 96/250 (38.4%) patients, 321/3600 injections (8.9%) caused local reactions in 89/250 (35.6%) and 40/3600 injections (1.1%) caused systemic reactions in 23/250 (9.2%). Initial SCIT treatment using NHD3 was safe and well tolerated in Chinese children and adolescents with AR and AA.