[Occupation-related lung diseases in hard metal production and manufacturing. An allergic process?].

The clinical heterogeneity of hard metal disease lung with its two basic forms, i.e. hart metal pneumonitis and hard metal asthma, supports the view of different pathogenetic mechanisms. Cobalt, which is generally considered the noxious agent in hard metal diseases, is cytotoxic on the one hand and allergenic on the other. Four typical, extensively investigated cases are presented, i.e. hard metal pneumoconiosis, hypersensitivity pneumonitis, toxic-irritative hard metal asthma and allergic cobalt asthma. The immunological results were negative in the patient with hard metal pneumoconiosis. A hard metal grinder with typical occupational hypersensitivity pneumonitis showed a high level of precipitating antibodies against Aureobasidium pullulans, a well-known antigen in humidifier fever and sequoiosis. The inhalative provocation test induced on both patients with hard metal asthma an immediate and prolonged, i.e. a dual asthmatic reaction. Only the patient with allergic contact eczema due to cobalt and a positive epicutaneous test of the delayed type and a positive scratch tests of the immediate type with cobalt chloride.