Cases of taste disorder following ingestion of pine nuts reported to the National Information Service

Objective: To describe cases where symptoms of taste disorder have been reported to the National Poisons Information Service (NPIS) and recorded on the UK Poisons Information Database (UKPID), particularly following the ingestion of pine nuts. Case series: Seven cases of taste disorder have been reported to the NPIS following ingestion of pine nuts. All patients were adult, three male and four female. In five cases symptoms were limited to an unpleasant, metallic taste particularly when eating (dysgeusia). Two patients also described headache, one of whom complained of xerosis and thirst. The symptoms developed up to two days after the ingestion of pine nuts and persisted for up to 2 weeks. On interrogating UKPID for all cases with symptoms of taste disorder, 251 cases were reported since Jan 2008. The most common agents causing this phenomenon were metals or metallic compounds. Essential oils (particularly Olbas Oil), bleach, descaler, chlorine, antifreeze, carbon monoxide and fungi were each associated with several cases of taste disturbance. Conclusion: The first incidence of dysgeusia as a result of ingestion of pine nuts was published in 2001. The first case reported to the NPIS was in 2008 which suggests this is a relatively recent phenomenon in the UK. There are various theories as to the cause of dysgeusia due to pine nuts including possible oxidation of oils in the nuts due to spoiling, presence of contaminants or nuts sourced from different species of Pinus trees.^1,2 The dysgeusia is harmless and resolves uneventfully but can be distressing for the patient who may not associate the symptoms with recent pine nut ingestion. Other causes of dysgeusia include, tooth decay, heavy metal poisoning, gastritis, certain drugs (e.g. metronidazole), chemotherapy or jaundice. If dysgeusia can be attributed to ingestion of pine nuts in the first instance and resolves within two weeks then patients may be reassured and unnecessary medications or investigations avoided. References: 1. Mostin M. Taste disturbances after pine nut ingestion. Eur J Emerg Med 2001; 8:76. 2. Munk MD. "Pine mouth" syndrome: cacogeusia following ingestion of pine nuts (genus: pinus). An emerging problem? J Med Toxicol 2010; 6:158–9.