[Acute encephalopathy caused by cyanogenic fungi in 2004, and magic mushroom regulation in Japan].

Two topics, related to mushroom poisoning of recent interest in Japan, have been presented. In autumn 2004, 59 cases of acute encephalopathy were reported across 9 prefectures in Japan (24 from Akita Prefecture with 8 deaths; age 48-93, average 70; female 14, male 10). Of 24 cases, 20 had kidney dysfunction. Four poisoned subjects showed no kidney trouble. Of the 24 poisoning cases, 23 people ate Pleurocybella porrigens, and one ate Grifola frondosa. The latter subject (female, late 40's) was receiving dialysis for more than 35 years. In August, she felt dizziness, headache and tinnitus. She visited hospital and asked to stay there. In the hospital she ate 5g of stewed G. frondosa and 10g of the same fungus boiled with chicken and taro on different days. Fourteen to 18 days after the eatings, she developed cramps and lost consciousness, and fell into a coma. Her cramp and coma continued for about 10 days almost until her death. Her symptoms caused by G. frondosa were similar to those observed for the above 23 cases of P. porrigens ingestion. Therefore, we concluded that encephalopathy experienced in Akita Prefecture caused by was the cyanogenic fungi such as P. porrigens , G. frondosa, Pleurotus eringii etc. Although the amounts of mushrooms eaten by poisoned subjects were not so clear, we estimated that the amounts of hydrogen cyanide (HCN) taken into human bodies exceeded the detoxication limit of HCN, resulting in HCN poisoning. However, it has not been proved that the encephalopathy is directly or indirectly caused by the HCN poisoning. Many typhoons came across Japan and landed 10 times in 2004, and mushroom size was larger than usual one, and HCN contents in fruit-bodies seemed to be increased especially in the late-stage of their growth. Thirteen species of magic mushrooms were prohibited by the law from 2002 in Japan. They include Copelandia (Panaeolus) cyanescens, Panaeolus papilionaceus, Panaeolus sphinctrinus, Panaeolus subbalteatus, Psilocybe argentipes, Psilocybe cubensis, Psilocybe fasciata, Psilocybe lonchophorus, Psilocybe subaeruginascens, Psilocybe subcaerulipes, Psilocybe subcubensis, Psilocybe tampanensis, and Psilocybe venenata.