Giant cell pneumonitis induced by cobalt.

Cobalt alone and in combination with tungsten carbide known as hard metal is capable of causing lung damage. This may vary from development of pulmonary oedema to asthma and fibrosing alveolitis. We report a case of giant cell interstitial pneumonitis caused by exposure to cobalt dust which was not identified as the etiological agent initially and hence led to progression of the disease. The patient subsequently improved following cessation of exposure and treatment with oral corticosteriods, thereby stressing the importance of occupational history in all cases of interstitial pulmonary fibrosis.