Polymerized Molecular Allergoid Alt a1: Effective SCIT in Pediatric Asthma Patients.

: Allergy to (Alt a), although often underdiagnosed, is a significant global health issue. In the allergen immunotherapy (AIT) field, novel therapeutic strategies are emerging, particularly with the advent of polymerized allergoids. This study aims to evaluate the efficacy of subcutaneous immunotherapy (SCIT) based on these innovative molecules in children with respiratory allergies, assessing clinical and functional parameters. : We enrolled 42 patients aged between 6 and 16 years, all of whom had allergic rhinitis (AR) and concomitant asthma and all of whom were monosensitized to Alt a. Between December 2020 and December 2021, 17 patients initiated SCIT with Modigoid for Alt a1, while 25 patients continued with standard therapy. At the initial visit (T0), all the patients underwent nasal and bronchial evaluation, including exhaled nitric oxide (eFeNO) measurement and spirometry. The Asthma Control Test (ACT) was used to evaluate the control of asthma symptoms. Patients were followed up every 6 months, with a comprehensive re-evaluation at 24 months (T1) replicating the initial assessments. : After 24 months of SCIT with the new polymerized molecular allergoid Alt a1 (Modigoid), children showed a statistically significant reduction in eFeNO levels, improved FEV1 values, and enhanced ACT scores. : SCIT with the new molecular allergoid Alt a1 significantly improves functional parameters (FEV1 and eFeNO) and subjective asthma symptoms (ACT scores) in children with AR and objective asthma signs. This treatment represents an effective preventive strategy that can be used to halt the progression of the classic atopic march from AR to asthma and potentially reverse the atopic march.