Assessment of early- and late-phase nasal obstruction in atopic patients after nasal allergen challenge.

In order to study the types of nasal obstruction in allergic rhinitis, nasal allergen challenge was performed in 18 atopic patients, compared with a control group consisting of 10 healthy volunteers. Passive anterior rhinomanometry was used as an objective evaluation of nasal airway resistance. A 100% increase of nasal airway resistance was considered to be a positive reaction. In the control group, no obvious nasal obstruction was recorded after nasal phosphate buffered saline challenge. In the patient group, nasal obstruction occurred only after challenge in 94% during the early phase and in 82% during the late phase. During the late-phase four major types of nasal obstruction were found, i.e. no nasal obstruction; one-sided nasal obstruction only; bilateral nasal obstruction; and alternating nasal obstruction. Of the four types, the alternating type was the most common (47%) type, especially during the late-phase.