Background: Previous studies have suggested that single-allergen–specific immunotherapy (SIT) may prevent sensitization to other airborne allergens in monosensitized children. We aimed to assess the prevention of new sensitizations in monosensitized children treated with single-allergen SIT injections in comparison with monosensitized patients given appropriate pharmacologic treatment for their disease.

Methods: A total of 147 children with rhinitis and/or asthma monosensitized to house dust mite were studied; 45 patients underwent SIT with adsorbed extracts and 40 patients underwent SIT with aqueous extracts for 5 years. The control group was comprised of 62 patients given only pharmacologic treatment for at least 5 years. Skin prick tests, medication scores for rhinitis and asthma, and atopy scores according to skin prick tests were evaluated at the beginning and after 5 years of treatment.

Results: All groups were comparable in terms of age, sex, and disease characteristics. At the end of 5 years, 64 out of 85 (75.3 %) in the SIT group showed no new sensitization, compared to 29 out of 62 children (46.7 %) in the control group (P = .002). There were no
differences between the SIT subgroups with regard to onset of new sensitization (P =.605). The patients developing new sensitizations had higher atopy scores (P = .002) and medication scores for both rhinitis (P = .008) and asthma (P = .013) in comparison to patients not developing new sensitizations after 5 years of SIT.

Conclusion: According to our data, SIT has the potential to prevent the onset of new sensitizations in children with rhinitis and/or asthma monosensitized to house dust mite.

Key words: Asthma. House dust mite. Immunotherapy. New sensitization. Rhinitis.