A case of acute duodenitis caused by Lampteromyces japonicus

A 71-year-old man was admitted to our hospital because of severe epigastric pain with concomitant vomiting and watery diarrhea. Prior to the acute onset, he had ingested some Lampteromyces japonicus, a poisonous mushroom. On EGD, a coarse granular mucosa with scattered erosions was diffusely observed in the second portion of the duodenum. Radiography demonstrated thickened mucosal folds with linearly or irregularly shaped barium flecks throughout the duodenum. Although neither illudin S nor its metabolites could be detected by High-performance liquid chromatogram (HPLC) method, his clinical course suggested that the acute duodenitis was caused by poisonous mushroom. During the subsequent 10 days, his symptoms rapidly improved. Repeated upper endoscopies showed a favorable improvement of his duodenal lesions. It is suggested that intramural damage by Lampteromyces japonicus involves only a superficial layer of the intestinal wall, and that the involvement improves rapidly.