Simultaneous development of two cases of eosinophilia-myalgia syndrome with the same lot of L-tryptophan in Japan.

Abstract

A newly recognized and well-described connective tissue disease, eosinophilia-myalgia syndrome, is thought to relate to L-tryptophan ingestion. The suspect L-tryptophan made in Japan has been distributed in Japan and in the United States. Different from many case reports of eosinophilia-myalgia syndrome in the United States, it has not been reported in Japan. We describe the first case reports of two Japanese patients. Eosinophilia-myalgia syndrome developed in these patients simultaneously, during L-tryptophan treatment by the same physician using the same lot of prescribed L-tryptophan. Furthermore, both patients had the following HLA types: HLA-Aw33(w19), -B44(12), and -DR6. These findings implicate the existence of another factor in the development of eosinophilia-myalgia syndrome in addition to the suspect L-tryptophan.