|Classification according to ICD-10|
Disorders of the sense of smell and taste
|ICD-10 online (WHO version 2019)|
Anosmia ( Greek ἀν- Toggle [ negative particle ]; ὀσμή osme , odor ') denotes the absence of the sense of smell or loss of sense of smell (olfactory loss).
The lack of olfactory perception can have various causes. Disturbances can occur in the area of the olfactory and the nasal-trigeminal system , depending on whether the olfactory nerve ( 1st cranial nerve ) or the trigeminal nerve ( 5th cranial nerve ) is affected.
Other causes for the lack of the sense of smell can be viral infections , chronic sinusitis , obstruction of the olfactory tract due to swelling of the mucous membranes as a result of an allergy , the side effects of drugs, brain tumors , depression as well as traumatic brain injury with avulsion damage to the olfactory nerves. Anosmia can also occur in the context of a dissociative disorder ( dissociation ). Symptomatic anosmia occurs in people with the Kallmann syndrome . Anosmia is also less common as an early symptom of neurodegenerative diseases such as Parkinson's disease . In rare cases, anosmia is also congenital.
The location of the disorder can be determined with an olfactory test ( olfactometry ). During the olfactory test, the trigeminal nerve is stimulated with acetic acid , for example . Relatively selective irritants for the olfactory nerve are hydrogen sulfide , vanilla or the scent of roses ( phenylethyl alcohol ). Both nerves together are stimulated by camphor , menthol , and peppermint . In the case of congenital anosmia, the disorder is often diagnosed late because the affected person does not initially notice their inability to perceive smells or certain tastes.
The effects of the loss of smell are often not recognized by outsiders or are played down as unimportant. Compared to other senses, the sense of smell is perceived as secondary, and the consequences of its absence are not sufficiently noted.
Psychological distress due to sudden anosmia
Sudden anosmia is associated with a significant loss of quality of life . It can be an indication of serious illnesses (such as Alzheimer's disease ) and is sometimes associated with considerable psychological stress. Psychological consequences include depression and constant fear of unpleasant odor , as even body odors that are not perceived can lead to social exclusion of the person concerned.
At most, people with congenital anosmia suffer from chronic fear of their own odor, as they do not miss the unknown odor experience.
General problems from anosmia
The sense of smell is largely responsible for the taste of food and drinks; people without this are limited to the five basic tastes ( sweet , sour , salty , bitter , umami ). This can lead to malnutrition or malnutrition. The motivation to eat something can decrease in the event of a sudden occurrence, or in both cases (innate and acquired) more salty or fatty foods are eaten in order to enjoy or intensify the basic taste experience.
Those affected can even endanger their lives due to the lack of awareness of warning signals. Failure to perceive putrefactive smells can lead to the consumption of spoiled food, which can lead to food poisoning. Life-threatening fires or escaping hot gases can be noticed too late. However, it is possible to “taste” strong smells, which requires extensive training.
Treatment for anosmia depends on the cause of the disorder. There is as yet no drug treatment for the anosmia that occurs as a result of a virus effect, which can also be permanent.
Anosmia in Culture
- In the Spanish novel Nunca sabrás a qué huele Bagdad , in German You will never know the smell of Baghdad , it is about congenital anosmia.
- In the novel Whispers of the Dead , in German corpse pallor , by Simon Beckett , the serial killer featured in it suffers from anosmia.
- In the six-part television series Parfum , investigator Nadja Simon is affected by anosmia.
- Hyposmia , the partial loss of the sense of smell
- Parosmia , a perception disorder in which familiar smells suddenly smell different.