Efficacy of sublingual specific immunotherapy in intermittent and persistent allergic rhinitis in children: an observational case-control study on 171 patients. The EFESO-children multicenter trial.

Sublingual-specific immunotherapy (SLIT) is considered as a valid treatment of respiratory allergies. However, there are few data on large sample size regarding its clinical role in 'real life' in term of reduction of symptoms, rescue medications and prevention of asthma in patients suffering from allergic rhinitis (AR) especially in children. We performed a multicenter, case-control study to evaluate the effect of SLIT in children (age 6-18 yr) with intermittent or persistent AR. 171 children (27% girls and 73% boys) with AR due to seasonal or perennial allergens were enrolled in a multicenter case-control study. Cases (n = 90) were defined as patients with intermittent (64%) or persistent (36%) AR who were treated for at least two consecutive years with specific SLIT with the related allergen extracts (SLITone ALK-Abellò). Controls (n = 81) were defined as sex-age- and type of allergen matched AR children who were never treated with specific immunotherapy and had no asthmatic symptoms at the beginning of observation period. Main outcomes of the study were the rhinoconjunctivitis symptom score (SS) (sneezing, rhinorrea, nasal itch, congestion, ocular itch and watery eyes) with a ranging scale from 0 (=no symptoms) to 3 (=severe symptoms) and the medication score (MS) evaluating symptomatic drug intake (antihystamine and inhaled corticosteroids). SS and MS were evaluated at the end of the observational period in relation with the period, considering the last 12 months, in which patients suffered the highest symptoms levels (i.e., peak of relevant pollen season (seasonal AR) or during the period of maximum allergen exposure in case of perennial AR). Secondary outcome of the study was the development of asthma symptoms during the observation period. SS (mean +/- SD) was 4.5 +/- 2.5 in cases and 9.0 +/- 3.0 in controls (-50%) (p = 0.0001). MS (mean +/- SD) was 2.5 +/- 1.9 and 3.6 +/- 2.1 in the case and control groups, respectively (-31%) (p = 0.0001). At the end of the observation period asthma symptoms were present in 14 subjects in the case group (15%) and in 20 children (24%) in the control group (p = 0.13). New skin sensitizations appeared in 6% of cases (n = 2) and in 36% (n = 12) of the controls (p = 0.001). The EFESO trial shows that a 2-yr once daily SLIT treatment in children with intermittent or persistent AR is associated with lower symptom and medication scores in comparison with subjects treated with symptomatic drugs only.