100 persons ate curry and rice at a festival in Wakayama, Japan. Four persons died and about 75 persons became ill. Cyanide poisoning originally was the suspected cause, but the final diagnosis was deliberate arsenic contamination.
Diarrhea is common with arsenic, but rare with cyanide.
Cyanide poisoning causes anxiety, agitation, hyperpnea, hyperventilation, giddiness, headache, and mild hypertension, which are rare with arsenic poisoning. Administration of potent vasodilating amyl and sodium nitrite cyanide antidotes may be dangerous especially in this setting. Late sequellae of arsenic poisoning include peripheral polyneuropathy and bone marrow depression with anemia, leukopenia, and pancytopenia, while a Parkinsonian-like condition is the major sequella of severe acute cyanide poisoning. Pancytopenia in the survivors from the Wakayama event led to the diagnosis of arsenic poisoning. Arsenic and arsine.