Risk factors and strategies associated with subcutaneous allergen immunotherapy in children

Subcutaneous immunotherapy (SCIT) is effective for allergic diseases, but data on systemic adverse reactions (SRs) in children remain limited. This study evaluated the prevalence, severity, and risk factors for SRs following standardized house dust mite SCIT (HDM-SCIT) in East Chinese children.

We analyzed data from 427 children (aged 5-16 years) who received HDM-SCIT between January 2015 and April 2021. We examined the occurrence, timing, and management of SRs, and investigated associations with age, sex, BMI, allergens, IgE, allergic disease types, and injection doses/timing.

SRs occurred in 5.60 % (755/13477) of injections. Incidence was higher in younger age groups (7.25 % in 5-7 years). All reactions were mild to moderate (85.96 % Grade I, 13.38 % Grade II, 0.66 % Grade III), managed without hospitalization. Univariate analysis identified sex, age, allergic disease, injection dose, and time as risk factors (all P < 0.05). Multivariate analysis revealed female children, particularly in the younger age groups with multiple allergic diseases were more prone to SRs, with greater severity, especially in the 5-7 year age group (P < 0.01).

HDM-SCIT is safe and well-tolerated in children. Key risk factors include age, sex, allergic disease multiplicity, initial treatment dose, and timing. Younger female children with multiple allergic diseases require special attention for potentially severe SRs, emphasizing careful dose management in this demographic.