[Exogenous allergic alveolitis: 22 year follow-up of malt worker's lung].

This is a report on a case of exogenous allergic alveolitis or malt workers' lung where no irreversible damage to the lung occurred despite a course of 22 years. The diagnosis was arrived at by means of a re-exposure test at the place of work followed by bronchoalveolar lavage. Reasons are being sought for the failure of all other diagnostic methods to diagnose exogenous allergic alveolitis. The disease is distinguished from the "organic dust toxic syndrome" by differential diagnosis.