Frequency of acute systemic reactions in patients with allergic rhinitis and asthma treated with sublingual immunotherapy

Background Several studies have demonstrated the efficacy and safety of sublingual immunotherapy in the treatment of respiratory allergy. Objective To determine the frequency of systemic adverse reactions in patients treated with standardized extracts of sublingual immunotherapy. Methods Allergic patients with rhinitis with or without asthma and sensitized to at least 1 allergen were included. Increasing doses of standardized allergens were administered until reaching an average dose accumulated of 7,200 U after 26 weeks of treatment. Adverse events were graded according to the European Academy of Allergy and Clinical Immunology immunotherapy position paper. Results Forty-three patients with a median age of 11 years (interquartile range, 8-20 years) were included. All the patients had allergic rhinitis, and 63% had asthma; they were sensitized mostly to Dermatophagoides pteronyssinus and Dermatophagoides farinae . Four patients (9%) presented with an immediate and 1 (2%) with a late systemic reaction. In total, 7 systemic reactions occurred in 23,154 doses, and all were associated with wheezing or worsening of nasal symptoms (grade 2); in addition, 1 patient had angioedema and urticaria (grade 3). Conclusions In this group, systemic reaction frequency was 11.6%, and all were classified as grade 2 or 3. Further assessments in larger samples of patients are required in the context of randomized controlled trials.