Acute Cycas seed poisoning in Taiwan.
OBJECTIVE
The seeds of cycads contain cycasin and neocycasin, which belong to the family of cyanogenic glycosides. These glycosides of cycads are considered pseudocyanogenic with little potential to liberate hydrogen cyanide as other cyanogenic glycosides do. This study investigated the clinical spectrum of Cycas seed poisoning and its cyanogenic potential.


METHODS
This was a retrospective chart review conducted at the Poison Control Center in Taiwan (PCC-Taiwan) from 1990 to 2001.


RESULTS
Twenty-one cases of Cycas seed poisoning were identified. The reasons for seed ingestion were misuse as an edible food (70%), health promotion (10%), cancer prevention (10%), cosmetic use (5%), and gastrointestinal discomfort (5%). All patients had eaten the seeds after washing and cooking them. The time from ingestion to the onset of symptoms ranged from 30 min to 7 h (mean 2.8 h); patients had ingested between 1 to 30 seeds. Respiratory depression did not occur. Severe vomiting was the most striking symptom. All patients except one presented with gastrointestinal disturbance, and 90% sought medical care at the emergency department. Within 24 h, all patients had recovered. Six patients had blood cyanide or thiocyanate levels measured. Although the levels were higher than normal, they did not reach the toxic range.


CONCLUSIONS
The cyanogenic potential of Cycas seeds is documented in our cases. The gastrointestinal symptoms were severe enough that most patients sought medical attention but recovery was quick and complete.
Chang
Shy-Shin
SS
Department of Emergency Medicine, Chang-Gung Memorial Hospital, Kweishan Hsiang, Taoyuan, Taiwan.
Chan
Yi-Ling
YL
Wu
Ming-Ling
ML
Deng
Jou-Fang
JF
Chiu
Te- Fa
T
Chen
Jih-Chang
JC
Wang
Feng-Lin
FL
Tseng
Ching-Ping
CP
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003486:Cyanides / Q000097:blood; D029784:Cycas / Q000506:poisoning*; D005260:Female; D006027:Glycosides / Q000737:chemistry / Q000506:poisoning; D006801:Humans; D006856:Hydrogen Cyanide / Q000737:chemistry; D008297:Male; D008875:Middle Aged; D011039:Poison Control Centers; D011041:Poisoning / Q000097:blood / Q000503:physiopathology* / Q000628:therapy; D012189:Retrospective Studies; D012639:Seeds; D013624:Taiwan; D013861:Thiocyanates / Q000097:blood
D003486:Cyanides; D006027:Glycosides; D013861:Thiocyanates; D006856:Hydrogen Cyanide; C031760:thiocyanate