Review of Symptoms Assessment During Nasal Allergen Provocation in Patients with Allergic Rhinitis

Background: Allergic rhinitis is the most prevalent allergic disease. Nasal provocation tests (NPTs) may be useful for its clinical diagnostic and therapy monitoring although they are mostly used in clinical research. However, the lack of standardisation in the symptoms assessed and the variety of instruments used make effective comparison between studies difficult. Objective: To review the published literature searching for instruments assessing nasal symptoms during NPTs for allergic rhinitis. Methods: Pubmed and Embase electronic databases were reviewed, looking for all methods in- cluding an instrument assessing symptoms during or following NPTs. Studies on animal models, pediatric subjects, and patients without allergic rhinitis were excluded. Studies were also excluded if they did not assess nasal symptoms during or following the NPT. Only NPT studies performed with allergen extracts or histamine were included. Results: A total of 520 studies were retrieved, from which 81 different instruments from 81 studies were included in the present analysis. There was no instrument reporting a validation process for the assessment of symptoms during NPTs. From the remaining instruments, the most common symptoms assessed were rhinorrhea (67), sneezing (70), congestion (67), and nasal pruri- tus (50). The most frequently used type of scales among those instruments was the four-point Likert scale (39), although different methods were used. Conclusions: This review illustrates the large variety of symptoms and methods used to as- sess the aforementioned NPTs. The lack of validation studies suggests the need to develop and validate a standardized in- strument assessing symptoms following NPTs.