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.