Coseasonal sublingual immunotherapy reduces the development of asthma in children with allergic rhinoconjunctivitis

Background We wondered whether short-term coseasonal sublingual immunotherapy (SLIT) can reduce the development of asthma in children with hay fever in an open randomized study. Objective We sought to determine whether SLIT is as effective as subcutaneous immunotherapy in reducing hay fever symptoms and the development of asthma in children with hay fever. Methods One hundred thirteen children aged 5 to 14 years (mean age, 7.7 years) with hay fever limited to grass pollen and no other clinically important allergies were randomized in an open study involving 6 Italian pediatric allergy centers to receive specific SLIT for 3 years or standard symptomatic therapy. All of the subjects had hay fever symptoms, but at the time of study entry, none reported seasonal asthma with more than 3 episodes per season. Symptomatic treatment was limited to cetirizine, loratadine, nasal budesonide, and salbutamol on demand. The hay fever and asthma symptoms were quantified clinically. Results The actively treated children used less medication in the second and third years of therapy, and their symptom scores tended to be lower. From the second year of immunotherapy, subjective evaluation of overall allergy symptoms was favorable in the actively treated children. Development of asthma after 3 years was 3.8 times more frequent (95% confidence limits, 1.5-10.0) in the control subjects. Conclusions Three years of coseasonal SLIT improves seasonal allergic rhinitis symptoms and reduces the development of seasonal asthma in children with hay fever.