ABSTRACT
Olfactory dysfunction is observed in different groups of palliative care patients. It can alter food choices and intake and subsequently exacerbate disease states. Its negative influence on quality of life was also repeatedly demonstrated.
The sense of smell is a function of a complex olfactory pathway projecting from receptor cells in the nasal cavity up to the orbitofrontal cortex, thalamus, hypothalamus, basal ganglia and hippocampus. Olfaction can be altered at every level of this pathway. The causes of hyposmia are mechanical obstruction or bypass of the airflow through the olfactory mucosa, neurotoxicity of pharmacotherapy (primarily antineoplastic) and radiotherapy, chronic renal and hepatic failure, neurodegenerative diseases and normal aging. Apart from a decreased sense of smell, other olfactory phenomena, that is, parosmia, can be observed. In every case the management of olfactory dysfunction must be tailored according to its particular mechanism and special needs of a patient (e.g., termination of the causative drug therapy, compensation of nasal airflow deficit). General management strategies to improve chemosensory abnormalities include eating a balanced and nutritious diet with adequate calories, reducing the consumption of foods that taste metallic or bitter, serving foods at cold temperature to reduce unpleasant flavors and odors, practicing good oral hygiene, using sialogogues and saliva substitutes, adding seasonings and spices and utilizing flavors. Olfactory training may also be considered.
