[Nasal and bronchial respiratory pathology in a group of workers exposed to phthalic anhydride]

Each subject answered a questionnaire, and was submitted to respiratory function tests, bronchial challenge with methacholine and ultrasonic "fog", specific challenge with fumes and powder of PA, measuring nasal and bronchial resistances at the same time by means of a plethysmograph. Serum specific IgE against PA were assessed by the method E.L.I.S.A. Inhalation of "fog" induced a positive nasal response (i.e. nasal resistance increase greater than 70% from baseline) in 73.7% of the subjects, whereas only 3 subjects had a positive bronchial response; specific challenge with PA induced a positive nasal response in 75% out of the subjects, whereas a positive bronchial response was observed in only one subject. 22.7% of the subjects had bronchial hyperreactivity to methacholine. In none of the subjects specific IgE against PA were detectable. We conclude that PA acts as an aspecific irritative agent of airways, particularly of nasal airways.