Long-term prognosis of immediate hypersensitivity type of occupational laryngitis

The present study investigated, for the first time, the long-term prognosis of hypersensitivity type of occupational laryngitis (OL). Thirteen patients with OL diagnosed in 1990-1993 at the Finnish Institute of Occupational Health participated in a questionnaire follow-up study. The records of the primary diagnostic investigations were also reviewed. The mean follow-up time was 12.5 (range 11-15) years. The mean age of the study subjects was 51.5 (range 32-64) years; nine (69%) were women. In addition to OL during the primary examinations, two patients were diagnosed to have occupational asthma, and nine patients occupational rhinitis. During the follow-up, six additional patients had developed asthma. Asthma had thus been diagnosed in 8 of the 13 (61%) patients. At present, nine patients (69%) were non-employed. Of these, seven were on work disability pension, of whom six had occupational or non-occupational asthma in addition to OL. The remaining four patients (31%) were still working: three had training for some other type of work, and one had been transferred to another job. None of them had developed asthma during the follow-up. The current study, based on a small series, suggests that many of the patients with previously diagnosed OL developed asthma and were not employed.