Preseasonal local allergoid immunotherapy to grass pollen in children: a double-blind, placebo-controlled, randomized trial

Background: We assessed the efficacy of preseasonal local allergoid immunot herapy in a group of children with asthma and/or rhinitis and/or rhinoconju nctivitis due to grass pollen. Methods: We randomly assigned 24 children allergic to grass pollen to recei ve local allergoid immunotherapy for 3 months before the pollen season and 24 such patients to receive identically appearing placebo. The immunotherap y consisted of tablets of monomeric allergoid grass pollen allergens held i n the mouth until they dissolved and then swallowed. The study was double-b lind. Symptoms and medications were scored on diary cards during the pollen season. Nasal eosinophil cationic protein levels were measured by the mono clonal antibodies EG1 and EG2 outside the pollen season and at low and at h igh pollen concentration during the pollen season. Results: The active-treatment group had a statistically significant reducti on of total symptoms (P < 0.05), especially bronchial symptoms (P < 0.05), in comparison with the placebo group. Immunotherapy was well tolerated and compliance was good. Nasal levels of EG2 and EG1 increased significantly du ring the pollen season, but there was no difference between groups. EG2/EGI increased significantly only in the placebo group during natural allergen exposure (P < 0.01). Conclusions: Our results suggest that this immunotherapy is effective for t he treatment of asthma due to grass pollen in children.