Symptomatic relief after grass nasal immunotherapy: lasting efficacy after 4-5 years

Twenty-two patients with rhinoconjunctivitis from grass pollen allergy, who were initially recruited for a one-year open clinical trial with local nasal immunotherapy (LNIT), continued the treatment for 2 or 3 more years. Three to four years after the end of treatment, they were reapproached and agreed to complete a questionnaire to evaluate their symptoms and rescue medications during the grass-pollen season. Twelve patients (54.6%) were almost free of symptoms, six patients (27.3%) complained of only minor symptoms, and four (18.1%) still had substantial symptoms. The median score for cumulative symptoms 4-5 years after stopping LNIT (112.5 points) was lower than before LNIT (291.6 points) and after the one-year clinical trial (138.2 points). The present observational study confirms the validity of LNIT as an alternative to conventional subcutaneous immunotherapy.