Abstract
A 52-year-old male welder, who had been exposed to metal fumes and nitric acid without adequate protective measures, presented with symptoms of cough, dyspnea, and fever. He was admitted to our hospital, where bronchoscopy revealed hemorrhagic bronchoalveolar lavage fluid. He was diagnosed with diffuse alveolar hemorrhage (DAH) due to occupational inhalation of metal fumes and nitric acid. Treatment with corticosteroids led to a rapid recovery without pulmonary sequelae. The case highlights the potential for metal fumes and/or nitric acid to induce DAH, the effectiveness of corticosteroids in treating the condition, and the critical importance of occupational protective measures.