Phantosmie

Phantosmia, also known as phantom smell, is a type of olfactory hallucination in which a person perceives odors that have no identifiable source. The experience can be intermittent or persistent and is often described as smells of burning, smoke, chemical products, or foul odors. Some individuals may notice accompanying nasal irritation, headaches, or anxiety related to the unfamiliar sensation.

Causes and associations

Phantosmia can arise from a range of conditions affecting the nose, sinuses, or brain. Local nasal or sinus disease, such as chronic rhinosinusitis or nasal polyps, can contribute. Neurological factors include temporal lobe epilepsy, brain tumors or other lesions, migraines with aura, or post-traumatic changes after head injury. It may also occur with neurodegenerative diseases in older adults, such as Parkinson’s disease or Alzheimer’s disease. Infections, exposure to environmental toxins, medications, or recent viral illnesses (including respiratory infections) have also been reported as possible triggers. In many cases, no clear cause is identified.

Diagnosis

Diagnosis relies on a detailed medical history and physical examination, including a focused assessment of smell function. Olfactory tests may be performed to characterize anosmia, hyposmia, or parosmia versus phantosmia. When indicated, neurological evaluation and brain imaging (such as MRI or CT) are used to identify structural or epileptic causes. Management of underlying conditions is a central focus of diagnosis and treatment.

Management and prognosis

Treatment aims at addressing the underlying cause when possible. This may involve treatment of sinus disease, nasal steroids, or nasal irrigation; management of migraines or seizures; or adjustment of medications. Some cases resolve on their own, while others persist and may require multidisciplinary care, including neurology, ENT, or psychiatry. The prognosis varies with etiology and duration.