[A case of pneumonitis and hepatic injury caused by a herbal drug (sho-saiko-to)].

We report a case of pneumonitis and hepatic injury caused by Sho-saiko-to. A 56-year-old man was admitted to our hospital because of hepatic disorder. The levels of serum transaminases returned to normal within two months without specific treatment and he was discharged. Four weeks later, he was readmitted because of severe pneumonitis and mild hepatic disorder. Under the suspicion of drug-induced pneumonitis, all medications were discontinued and high-dose glucocorticoid including "pulse therapy" was given. Consequently, pneumonitis and hepatic function markedly improved. Careful history taking revealed the ingestion of Sho-saiko-to before both admissions. Lymphocyte stimulation test against Sho-saiko-to was positive. Challenge test using Sho-saiko-to resulted in decrease of PaO2 and elevation of serum transaminases. Based on these findings, the diagnosis of pneumonitis and hepatic injury induced by Sho-saiko-to was established.