Hard metal disease: clinical aspects.

On the basis of the data available in the literature and of our experience, the clinical patterns of respiratory troubles which can be observed in workers exposed to inhalation of hard metal dusts can be schematized as follows: Irritation forms, mild and transient, or severe up to pulmonary oedema, dose-correlated, which occur in all subjects exposed to sufficiently high atmospheric concentrations; Asthmatic forms, either reversible after cessation of exposure or persistent after stopping the exposure, which occur in a relatively low percentage of exposed subjects and also apply to the states quoted below; Dyspnoic patterns due to alveolitis (lymphocytic alveolitis with inverted helper/suppressor ratio, or giant cell-eosinophilic alveolitis, with or without fibrotic changes of pulmonary interstitium); Interstitial sclerotic lung disease, associated with or without an alveolitic component. The present diagnostic potentialities, particularly bronchoalveolar lavage (BAL), have helped in defining the clinical patterns and have confirmed the fundamental role of individual susceptibility in the occurrence of clinical manifestations (with the exception of the irritation forms), but so far have not yet enabled us to clarify whether the different clinical patterns are the results of a single pathogenetic mechanism or constitute pathogenetically distinct entities.