Local intranasal immunotherapy for ragweed allergic rhinitis. I. Clinical response

Local nasal immunotherapy (LNIT) of ragweed allergic rhinitis was studied in a double-blind controlled trial. Sixty-seven subjects were divided into three groups. Twenty-one received unmodified ragweed extract (RW), 24 received a glutaraldehyde polymer of ragweed extract (PRW), and 22 received placebo. Mean symptom/medication scores during the season were 2.12, 2.76, and 3.93 for the RW, PRW, and placebo groups, respectively. Both RW- and the PRW-treated group scores were significantly lower than those of the placebo group (p less than 0.01, and p less than 0.025, respectively). The results of the patients' self-evaluations indicated that therapy was effective in 71%, 59%, and 41% for the RW-, PRW-, and placebo-treated groups, respectively. Adverse reactions to treatment were limited to the upper respiratory tract and were noted by all patients. They were significantly more severe in the RW-treated patients than those in the PRW- or placebo-treated groups. We conclude that LNIT is an effective therapy for ragweed allergic rhinitis. The use of a PRW decreased adverse reactions significantly while slightly decreasing the therapeutic benefit.