Phantosmia is a form of olfactory hallucination. While most olfactory hallucinations are caused by a misinterpretation of a physical stimulus, such as in the case of parosmia, phantosmia is the perception of a smell in the absence of any physical odors. The odor can range from pleasant to a disgusting smell. Although the causes of phantosmia are debated, it is often comorbid with psychological disorders such as schizophrenia, mood disorders, Parkinsons disease, epilepsy, neuroblastoma, and frequent migraines.
Claudius Galenus also mentioned olfactory hallucinations in his work and stated that these hallucinations constitute the signs of an oncoming disease.
Different types of phantosmia include unirhinal, episodic, recurrent phantosmia, where the activation of brain's GABAergic system seems to play a role in the inhibition of the unirhinal phantosmia. Treatments for phantosmia range from drug therapies (e.g., venlafaxine) and brain stimulation therapies to invasive surgical procedures involving removal of the olfactory bulbs or olfactory epithelium.
The word phantosmia is a noun of Greek origin. It is composed of two words: (1) phanto meaning phantom and (2) osmia-Greek: osme meaning smell.
Read more about Phantosmia: The Olfactory System, Olfactory Perception, Causes, Diagnosis, Development, Symptoms, Treatment, Gender and Occurrence, Pregnancy