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Abstract

The term cacogeusia comes from the Greek adjective kakos (bad, unpleasant) and the Latin noun gustum (taste). It translates as ‘bad taste’. It is used to denote a *gustatory hallucination or illusion presenting in the form of an unpleasant taste. Cacogeusia is often associated with – and confused with – *cacosmia. Etiologically, it is associated primarily with nutritional disorders (notably zinc deficiency), metal toxicity, seafood toxins, medication use, illicit-substance use, dental conditions, sinusitis, and local infections of the upper respiratory pathways or oesophagus. In some cases it can be attributed to central disorders, for example, following systemic infectious disease or traumatic brain injury. Cacogeusia is classified as one of the *chemosensory disorders. Sometimes specific types of cacogeusia are given independent names, such as metallogeusia (a metallic or bitter taste) and torquegeusia (a burned or smoky taste).