Local intranasal immunotherapy with allergen in powder in atopic patients sensitive to Parietaria officinalis pollen.

Local Intranasal Immunotherapy (LII) is a new approach to the treatment of allergic rhinitis due to the pollen of Parietaria officinalis. The aim of this study was to verify the usefulness of LII and to determine the proper doses. Twenty adult patients all presenting a sensitization to the pollen of Parietaria officinalis were randomly divided into two groups: 15 received the treatment and five were the control group. Treatment started before the beginning of the pollinic season of Parietaria officinalis and continued during the season. The extract used was an active extract of macronized powder Parietaria officinalis pollen in increasing doses. Doses were determined periodically with specific nasal provocation tests. Results in the treated group compared to the control group were statistically significant if one considers the increase in threshold sensitivity in the nasal provocation test, the diminution of clinical symptomatology and the quantity of drug required to control symptoms in the treated group. The side effects were few; it was only in one case that the treatment had to be interrupted. LII for allergic rhinitis due to the pollen of Parietaria officinalis seems an effective and practicable method even during the pollinic season.