Interstitial lung disease related to occupational hard metal exposure: two case reports

Background: Hard metal lung disease (HMLD) is a relatively less known occupational interstitial lung disease, and instances of HMLD resulting from para-occupational exposure are rarely reported. Case presentation: This paper presents two cases of interstitial lung disease caused by exposure to hard metal. The first case involves a 37-year-old Taiwanese man who had worked at a grinder station for hard metal materials for 12 years without respiratory protective equipment. He experienced a dry cough and exertional dyspnea, and his chest imaging and pathology findings were consistent with the features of usual interstitial pneumonia. Analysis of his lung tissue revealed the presence of tungsten and cobalt. The second case involves a 68-year-old Taiwanese woman, the mother of the first patient, who had hand-washed her son’s workwear. She experienced a dry cough and had similar imaging findings to her son. After her son left his job, they both exhibited improved symptoms and lung functions with nintedanib treatment. These findings suggest a diagnosis of HMLD and interstitial lung disease resulting from para-occupational exposure to hard metal dust. Conclusions: The diagnosis of HMLD relies on obtaining a detailed occupational exposure history. If HMLD is diagnosed, discontinuing exposing to hard metal dusts can lead to improved lung function.