Sublingual versus subcutaneous allergen immunotherapy in bronchial asthma: A randomized controlled trial

Background Asthma affects 300 million individuals worldwide. It is a serious global health problem affecting all age groups. The significance of eosinophilic inflammation in asthma is well established. Allergen immunotherapy (AIT) acts by increasing tolerance to specific antigens to which individuals demonstrate clinical sensitivity. Objectives Evaluate the efficacy and safety of sublingual immunotherapy (SLIT) versus subcutaneous immunotherapy (SCIT) as regards clinical response, total immunoglobulin E (IgE), and sputum eosinophil as well as adverse effects. Methods This randomized clinical trial included 100 patients with bronchial asthma who were randomly allocated into two groups: the SLIT group (n = 50) and the SCIT group (n = 50). Patients were given a full allergy history, symptoms, and medication scores; a skin prick test; total IgE for allergens, and a sputum eosinophil count. After the end of treatment, the efficacy, as well as side effects of both treatment arms, were evaluated at 6, 12, and 18 months. Results Both SLIT and SCIT were equally effective. Success rates have been demonstrated to be as high as 86-88%. There was a statistically significant decrease in symptom and medication scores, Total IgE levels, and sputum eosinophil results after treatment (P < 0.001). However, no difference was found between groups regarding the efficacy of treatment. SLIT was significantly safer than SCIT (P < 0.001). Conclusion Both treatment modalities were equally effective in treating asthma, but SLIT had a higher safety profile than SCIT.