Abstract
Purpose: In a previous study it was established that children with attention deficit hyperactive disorder (ADHD) and autistic spectrum disorders (ASD) had regressed during pollen seasons. The purpose of this study was to determine if these children regressed on direct nasal pollen challenge.
Design: A double‐blind crossover placebo‐controlled nasal challenge study.
Materials and Methods: Twenty‐nine children with ASD and 18 with ADHD comprised the population. The study was a double‐blind crossover with nasal instillation of a pollen extract or placebo on alternate weeks during the winter. The pollens used were oak tree, timothy grass and ragweed. The dose insufflated into each nostril was 25 mg (±15%) of each pollen.
Results: Sixteen of 29 (55%) children with ASD and 12 of 18 (67%) children with ADHD or a total of 28 of 47 (60%) children regressed significantly (p<0.01) from their baseline. Nasal pollen challenge produced significant neurobehavioral regression in these children. This regression occurred in both allergic and non‐allergic children and was not associated with respiratory symptoms. There was no correlation to the child's IgE level, positive RAST pollen tests, or skin tests.