Diffuse Alveolar Hemorrhage Associated with Herbal Medicine: A Case Series and Literature Review

Although there have been several reports of drug-induced pneumonitis caused by herbal medicines in recent years, herbal medicine-induced diffuse alveolar hemorrhage (DAH) is rare. We herein report two cases of DAH associated with herbal medicines. Patient 1 developed dyspnea and hemoptysis after receiving jidabokuippo. Patient 2 developed a fever and dyspnea after taking otsuji-to. Both patients exhibited severe respiratory failure, and bronchoalveolar lavage revealed bloody fluid that confirmed the diagnosis of DAH. In both patients, discontinuation of herbal medicines and corticosteroid therapy resulted in significant improvement. These cases highlight the potential risks of DAH associated with herbal medicines.