Induction of nasal late-phase reactions by insufflation of ragweed-pollen extract

Abstract

We studied changes in NAC in 17 ragweed-sensitive individuals after intranasal ragweed-challenge testing. All patients experienced immediate symptoms of sneezing, rhinorrhea, and nasal congestion that were associated with marked decreases in NAC (mean = 68%). In 10 trials patients also experienced late (>0 hr) symptoms of nasal congestion with or without rhinorrhea; the mean late NAC decrease in this group was 42%. In contrast, no late symptoms were noted in nine trials, and the mean NAC decreased 5% in this group (p < 0.003). Attempts to passively transfer immediate or late nasal sensitivity to one individual by spraying the nasal cavity with IgE antibody—containing serum, by packing the nose with cotton pledgets soaked in serum, by injecting serum directly into the inferior turbinate, and by transfusion with IgE-containing serum were not successful. We conclude that symptomatic late-phase reactions occur in the nose after intranasal challenge in about 50% of patients and that these symptomatic reactions can be confirmed objectively by rhinomanometry.