Star fruit intoxication in uraemic patients: case series and review of the literature

Star fruit, belonging to the Oxalidaceae family, species Averrhoa carambola, is a popular fruit among Orientals. There have been reports of hiccup, confusion, and occasional fatal outcomes in uraemic patients after ingestion of star fruit. An excitatory neurotoxin from star fruit has been implicated although the exact nature of this toxic substance has not been identified. A group of seven patients is described from the dialysis centres at Queen Mary and Tung Wah Hospitals who developed symptoms including hiccup, confusion, vomiting, impaired consciousness, muscle twitching and hyperkalaemia shortly after ingestion of star fruit. Symptoms of most patients resolved after intensified dialysis or spontan­eously, and no mortality was observed. The close temporal relationship of ingestion of star fruit and onset of symptoms strongly suggests the existence of a causal relationship between the two. It is recommended that uraemic patients should totally abstain from star fruit due to these rare but potentially fatal complications. The clinical manifestations of other reported series and current evidence for the possible candidate(s) of the neurotoxin are discussed. (Intern Med J 2003; 33: 314−316)