Effectiveness and adverse reactions to subcutaneous immunotherapy in children with allergic rhinitis/asthma

Adverse reactions, which are mostly local and rarely systemic, can be seen during subcutaneous immunotherapy (SCIT). It was not possible to continue SCIT at times due to systemic reactions. The purpose of the present study was to identify the incidence and risk factors associated with adverse reactions during subcutaneous allergen-specific immunotherapy (AIT).

A total number of 344 patients under 18 years old with allergic rhinitis and/or asthma who underwent SCIT between 2005 and 2021 were included in the study. Demographic characteristics of the patients, laboratory findings [Total Immunglobulin E(IgE), aeroallergen prick test, inhaler, and allergen specific IgE(sIgE) and eosinophil counts], and adverse events observed during AIT were recorded retrospectively. Descriptive and univariate/multivariate logistic regression analyses were used to identify risk factors for adverse events.

Among 344 patients, 33.4% (n = 115) were female, mean age was 133.1 ± 41.0 months, and 42.2% (n = 145) were >12 years old. One hundred-thirty eight (40.1%) of the patients were mono-sensitized, 47 (13.7%) had asthma, 207 (60.2%) allergic rhinitis, and 90 (26.2%) asthma and allergic rhinitis. Single allergen content was administered to 187 (54.4%) patients (62 mite, 114 grass mix, 11 olea), and multiple allergens to 157 (45.6%) patients (121 pollen mix, 36 other (mite/alternaria)]. A total number of 33.008 injections were administered. 840 adverse reactions (262 (31.1%) at up-dosing phase, 578 (68.8%) at maintenance phase) in 195 (56.7%) patients were observed. Among the adverse reactions, 632 (75.2%) were local, 160 (19%) large local, and 48 (5.7%) (39 at maintenance, 9 at up-dosing) (in 31 patients) were systemic (28 Grade 1, 12 Grade 2, 8 Grade 3). Adrenalin was administered to 8 patients with Grade 3 systemic reaction (8/33008; %0.024). Adverse reactions, especially local ones, were seen more frequently in children under 12 years old (p < 0.001). Patients sensitized with grass pollen (p:0.01) and mite (p:0.004), and those who had received SCIT with pollen mixture had more adverse reactions than the others. More adverse reactions were observed in SCIT containing calcium-phosphate as adjuvant (p: 0.01). Local reactions were risk factors for large local (OR = 3.591, %95 CI:2.064-6.247, p < 0.001) and systemic (OR = 2.190, %95 CI:1.005-4.722 p = 0.046) reactions at univariate analyses. Total nasal symptom scores, Visual Analog Scale and asthma symptom control test decreased after one year of treatment (p < 0.01).

SCIT is a safe and effective treatment method in childhood that leads to improvements in all nasal symptoms and asthma after one year of treatment.