The Efficacy and Safety of Allergen-Specific Immunotherapy Administered Intralymphatically to Patients with Allergic Rhinitis over a 3-Year Period

Introduction: Allergen-specific immunotherapy (AIT) modifies the natural course of allergic diseases. Intralymphatic administration necessitates smaller quantities and has the potential to improve treatment adherence. However, its safety and effectiveness are still being investigated. Objective: This study aimed to evaluate the long-term efficacy and safety of intralymphatic allergen-specific immunotherapy with up to 3 allergens in patients with allergic rhinitis, during a 3-year follow-up. Methods: A cohort trial provided three allergen-specific immunotherapies 1 month apart. We assessed adverse events after each dosage. We assessed 3-year progression using the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) scale. ANOVA, the ROC curve, and logistic regression analyzed the data. Statistical significance was set at p < 0.05. Results: Thirty-six patients with allergic rhinitis were analyzed; the mean age was 35.8 ± 13.7 years, 86.2% were female, 27.8% also had asthma, and 19.4% also had allergic conjunctivitis. The improvement in symptoms was sustained for 3 years following the third month of treatment. Pain and erythema at the site of application were the most common adverse reactions; only 1 patient experienced anaphylactic distress. The RQLQ score was associated with the likelihood of experiencing an adverse reaction with an odds ratio of 1.8 (p = 0.04); the cutoff point for this score was 2.5 with an AUC of 0.70, a sensitivity of 92%, a specificity of 36%, a PPV of 42%, and an NPV of 90%. Conclusion: Allergic rhinitis patients get 3 years of symptom alleviation after the third intralymphatic dose of AIT. An RQLQ score over 2.5 may indicate poor reactions in the first half hour of treatment, even when anaphylactic shock is unlikely.