A double‐blind, placebo‐controlled trial of local nasal immunotherapy in allergic rhinitis to Parietaria pollen

Abstract

We assessed the efficacy and safety of local nasal immunotherapy (LNIT) using an extract in macronized powder form of Parietaria pollen, a very important allergenic plant in the Mediterranean and other parts of the world. Twenty-six patients aged 13-37 years, with seasonal allergic rhinitis to this pollen, were enrolled in a double-blind placebo-controlled trial, carried out from autumn 1991 to the end of June 1992. They were selected on the basis of a positive skin-prick test, radioallergosorbent test (RAST) and intranasal challenge to Parietaria antigen. Patients were randomly divided into two groups of 13; the first group was given Parietaria antigen, and the second placebo. We recorded mean weekly symptom scores and drug consumption for 17 weeks during the pollen season in the year 1992, and specific serum-IgE and IgG levels. Three patients in the active group withdrew from the study because of bronchial symptoms. A significant difference was observed in mean weekly nasal symptom scores, in drug consumption and in specific nasal threshold to Parietaria allergenic extract in the treated and control groups. No difference was observed in serum IgE and IgG levels. Serum IgE levels rose significantly only in the control group after the pollen season. This study indicates that LNIT may be a useful alternative to traditional subcutaneous immunotherapy in patients with allergic rhinitis.

Local nasal immunotherapy: experimental evidences and general considerations

“…Furthermore, dried-powder extracts significantly reduce nasal reactivity and show satisfactory clinical efficacy and absence of side effects (14,16-18, 22, 23). Finally, the theoretical risk of asthma attacks (due to allergen inhalation) has been envisaged, but this kind of side effect is only an anecdotal report (17). In some studies (11 -13) patients frequently experienced local side effects (sneezing, rhinorrhoea, nasal blockage).…”

Local immunotherapy: pharmacokinetics and efficacy

“…So far, 21 studies are available for LNIT, and 14 of them were properly performed (43)(44)(45)(46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56), Of these, 13 report a significant improvement of rhinitic symptoms. Furthermore, a reduction of the nasal reactivity and local immunologic response was found in some studies, while systemic immunologic changes were usually absent or equivocal: this may suggest that LNIT exerts its actions only on the target organ.…”

Neubewertung des Risikos von Test- und Therapieallergenen

“…Mit Ausnahme von vereinzelt beobachteten Asthmaattacken liegen in der Literatur keine Hinweise auf schwerwiegende Nebenwirkungen vor [20,43]. Mit Ausnahme von vereinzelt beobachteten Asthmaattacken liegen in der Literatur keine Hinweise auf schwerwiegende Nebenwirkungen vor [20,43].…”