What are the Causes of Phantosmia?

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People who suffer from Phantosmia often smell odors that they describe as metallic, chemical, sewage-like, foul, etc. This article explains what are some of most common causes of this disorder.
Meaning of phantosmia
Did You Know?
Phantosmia is more common in women than men.
Ew... something stinks, did someone leave the Munster out again?! Wonder what perfume that Linda is wearing? Any guesses what senses are we talking about? Yes, we are talking about the sense of smell.
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Your sense of smell is one of the most important senses that helps determine if a particular food is fit for consumption or not. Foods with strong acrid smell are deemed poisonous, whereas a sweet, fruity smell makes the food even more appealing. It is the combination of taste and smell that make up the flavor of a particular food.

When something has a particular aroma, it releases certain volatile odorant molecules which stimulate certain olfactory receptors present in our nose. This in turn sends an impulse via the sensory neurons to our brain. Our brain identifies the impulse and gives an appropriate response.

What is Phantosmia?

The name "phantosmia" is of Greek origin, it is derived from the words phant meaning phantom, and osmia meaning smell. In this condition, a person experiences hallucinations of smell. The person can detect smells that do not exist around them. In other words, it is the perception of the sense of smell in spite of the absence of any physical odor.

This perceived smell can be pleasant or disgusting. During the initial onset of this disorder, the person experiences these symptoms mostly once a month, and they usually lasts only for a few minutes. With time, the duration of symptoms increases―in some cases it can last all day. The duration between two such episodes gradually keeps decreasing. The phantom smell can easily change from one to another in the course of time.

Usually, phantosmia might begin with only one nostril, but slowly these symptoms also begin in the other nostril.

Common Causes of Phantosmia

The basic cause of this disorder is due to the malfunction of the neurons involved in the olfactory systems.

Parkinson's disease
This is a neurodegenerative disorder of the nervous system, characterized by tremors, rigidity of the body, and difficulty in movement. It was initially thought that phantosmia was one of the complications of the disease, but recent studies have shown that the olfactory hallucinations are one of the initial symptoms of this disease in some individuals.

Alzheimer's disease
This is a neurodegenerative disorder characterized by memory loss, speech problems, disorientation, mood swings, and lack of behavioral issues. This disease occurs due to the atrophy of the temporal lobe. As this area is associated with phantosmia, occurrence of these olfactory hallucinations is not uncommon.

Epilepsy
Epilepsy is a group of neurological disorders that are characterized by episodes of epileptic seizure. It can last for a very brief period to a long one. Usually, partial seizures are preceded by visual, audio, or olfactory hallucinations known as aura. Seizures in the temporal lobe causes the person to usually blackout during the seizure. Many people have reported to have experienced phantosmia before a seizure.

Schizophrenia
This is a mental disorder that is characterized by abnormal behavior and failure to distinguish real from the imaginary. Brain imaging has shown an altered activity in the frontal lobes, hippocampus, and temporal lobes. The altered activity in the temporal lobes may sometimes cause these individuals to have olfactory hallucinations.

Mild depression
Another intriguing facet as to what may cause such hallucinations is its link to mild form of depression. Prescribing a person experiencing this disorder with some antidepressants has been observed to eliminate this disorder completely in many cases.

Migraine
This is a chronic disease affecting the autonomic nervous system. It is characterized by recurrent moderate to severe headaches. Sometimes, this can be accompanied by nausea, vomiting, sensitivity to light, sound, and sometimes even smell. Although rare, but phantosmia is seen to occur alongside the episode of severe headache. Treatment of the migraine also seems to alleviate phantosmia.

Neuroblastoma
This is a rare malignant cancer that mostly affects the olfactory nerve. This type of cancer is mostly observed in children younger than two years. Treatment of this cancer via surgery, radiation therapy, and chemotherapy may eradicate the tumor, but cause damage to the olfactory system and may give rise to phantosmia.

Others
Other causes of phantosmia may include injury to temporal lobe, infections of the upper respiratory tract, chronic swelling of mucous membrane of the nose that may or may not be an allergic reaction. Mild versions of this disorder can also be observed in pregnancy, especially in the later stages of gestation. The symptoms of this disorder are almost gone postnatal.
Prom Dresses
In most cases, phantosmia tends to relieve itself on its own (unless there is some underlying physiological disorder). Clinically, it is treated with antidepressants, nasal anesthetics, agents that could block the nose, nasal steroid sprays, or sedatives. In very extreme cases, surgery is required to eliminate this disorder.