Anosmia

What is anosmia?

Anosmia is the total loss of the sense of smell, in addition to the diminished ability to perceive flavors, so that its deficiency is related to loss of the sense of taste.

This pathology occurs when an intranasal inflammation or other obstruction prevents odors from entering the olfactory area; also, when the olfactory neuroepithelium is destroyed or when the filaments, bulbs, pathways or central connections of the olfactory nerve are destroyed.

Prognosis of anosmia

Anosmia is not always treatable, e.g. in patients with impairment of the nerve centers related to the nasal system or the deficiencies of old age. However, safety measures such as fire detectors or smoke alarms can be taken for these people to maintain a better quality of life and be safe.

Symptoms of anosmia

The main and most obvious symptom of anosmia is the loss of the ability to smell, but there may also be an initial change in the way things smell, with familiar things beginning to have no odor at all.

There are no specific treatments for anosmia,
but its causes can be treated.

Medical tests for anosmia

A doctor diagnoses a lack of the sense of smell by looking at:

• Family and personal history.
• An examination of the head, neck, and nose.

In some cases, you may also have:

• Tests to see if you can smell certain scents or odors.
• A blood test to check for a vitamin deficiency or other health problem.
• An MRI or CT scan to check for problems in the brain.

What causes anosmia?

Anosmia is mainly due to two reasons:

1. Pathologies that prevent air from reaching the olfactory receptors located in the upper part of the nostrils:
   • Common cold.
   • Rhinitis (allergic, vasomotor, infectious, medicinal…).
   • Sinusitis.
   • Deviation of the nasal septum.
   • Hypertrophy of the turbinates.
   • Tumors.

2. Influence of pathologies of the nervous receptor apparatus and of the central nervous pathway:
   • Cranioencephalic trauma (young adults).
   • Aging.
   • Neurodegenerative diseases, such as Alzheimer’s disease (older adults).

Other causes include:

• Previous head and neck radiation.
• Recent nasal or sinus surgery.
• Nasal and brain tumors.
• Toxins (the involvement of tobacco is uncertain).
• Drugs may contribute to anosmia in susceptible patients.

It should be noted that a loss of smell lasting several weeks in a middle-aged person may indicate the existence of nasosinusal polyposis, i.e. the growth of benign fleshy growths inside the nostrils that prevent air from reaching the upper part of the nose.

Can it be prevented?

Recommended preventive measures to avoid loss of smell include:

• Avoid prolonged exposure to toxic products or pollutants and, if unavoidable, wear a mask.
• Hydrate well.
• Avoiding contact with allergens.
• Flu vaccination, since the flu virus is responsible for a good number of anosmias.

Treatments for anosmia

There are no specific treatments for anosmia, but the causes of anosmia can be treated.

• Sinus infections and inflammation are treated with steam inhalations, nasal sprays, antibiotics and, in some cases, surgery.
• Tumors are surgically removed or treated with radiation therapy, but this treatment usually does not restore the sense of smell.
• Polyps in the nose are removed, in some cases restoring the ability to smell.

It is important to reassure the patient that in many cases the loss of the sense of smell may be temporary and return spontaneously, especially after common colds or viral infections.

Once the root cause of the loss of smell has been diagnosed, the problem should be addressed by correcting the underlying disorder if possible. The specific causes should be treated, although smell is not always restored, even after successful treatment of sinusitis.

1. Non surgical treatment: it would be pharmacological treatment: Sometimes a pharmacological treatment with antihistamines can be prescribed, if it is an allergy problem, use of vitamin A, etc. It is important that the patient avoids the use of nasal decongestants, since they usually have corticosteroids as active ingredient, which can lead to an increase in nasal congestion and inferior turbinates, due to a rebound effect.
2. Surgical treatment: If the cause of the loss of smell is the existence of a physical obstruction of the nostrils, it will be necessary to perform the corresponding surgical intervention to correct the problem, even being able to carry out and, at the same time, more than one of them. Nasal obstruction may be due to:
   • Hypertrophy of inferior turbinates: it will be necessary to carry out the procedure of induced radiofrequency of inferior turbinates.
   • Nasal septum deviation: it would be treated by performing a septoplasty.
   • Nasal polyps: it would be treated by performing a polypeptomy and/or ethmoidectomy.
   • Sinusitis: it would be treated by performing an endoscopic sinus surgery.

Which specialist treats it?

For a correct diagnosis and treatment of anosmia, it is necessary to consult an expert in Otolaryngology.