Background: Rhinomanometry measures nasal airflow that is frequently impaired in allergic rhinitis. Decongestion tests consist of spraying an intranasal vasoconstrictor drug to evaluate the reversibility of nasal airflow limitation. The aim of this study was to evaluate the decongestion test in patients with seasonal allergic rhinitis (SAR) caused by pollen sensitization, perennial allergic rhinitis (PAR) caused by sensitization to perennial allergens only, or mixed allergic rhinitis (MAR) caused by sensitization to both allergens.
Methods: One hundred twenty-three subjects (112 men and 11 women, mean age, 22.9 +/- 5.7 years) were studied; 40 subjects had PAR, 43 subjects had MAR, and 40 subjects had SAR. Total symptom score (including: nasal itching, sneezing, rhinorrhea, and nasal obstruction) was assessed. Rhinomanometry and decongestion tests were performed in all subjects.
Results: Nasal symptom severity was superimposable in the three groups (p was not significant). After decongestion tests, an increase of nasal airflow and a decrease of nasal resistance was shown in PAR (p < 0.01), MAR (p < 0.001), and SAR subjects (p < 0.001). The intergroup analysis showed that SAR patients had less reversibility than PAR (p < 0.01).
Conclusion: This study provides the first evidence of the different response to decongestion tests, taking into consideration the causal allergens.