LOSS OF SMELL
Each year, millions of Americans seek medical care for taste and smell disorders. Depending on the cause, loss of smell can be permanent or temporary.
The system that provides your sense of smell, consists of receptors in the mucous lining of your nose that sends information through nerves into your brain, this system is the olfactory system. You can lose your sense of smell if any part of the olfactory pathway is compromised, deteriorating, damaged, or destroyed.
- Hyposmia is a decreased sense of smell / ability to detect odors.
- Anosmia is the inability to smell anything at all.
- Parosmia is a distorted sense of smell, unable to detect the full range of the scents.
Symptoms of hyposmia or anosmia may be noticed gradually or suddenly, and include:
- Decreased or absent sense of smell
- Decreased sense of taste (flavor is the combination of taste and smell)
- Nasal blockage or congestion
- Persistent sneezing, nasal drainage, and itchy watery eyes
- Weight loss
Decreased sense of smell is not typically uncomfortable but can be accompanied by symptoms of chronic sinusitis, which may include frequent infections, facial pressure and pain, nasal obstruction, and drainage.
- Nasal congestion brought on by a cold, allergy, influenza, non-allergic rhinitis, or sinus infection. This is the most common cause.
- Nasal obstructions
- Head trauma
- Severe injuries to the upper part of the nose
- Severe upper respiratory infections
- Chemical inhalation / exposure
- Hormonal imbalances
- Nutritional deficiencies
- Birth defects / bone deformity
- Certain dental disorders
- Some prescription medications
- Some illegal drugs
- Radiation therapy (performed on the neck or head)
- Neurodegenerative disorders (dementia)
- Nasal & Brain masses
Loss of smell is the best indicator of coronavirus infection, usually manifesting long before other common symptoms such as fever or fatigue. Sometimes loss of smell is the only noticeable symptom.
Coronavirus causes loss of smell by damaging cells in the nose supporting neuroreceptors that transmit scent-based information to your brain. In most cases, the receptors themselves remain unharmed. Sense of smell usually returns within a few weeks. However, it’s common for COVID-19 patients to lose their ability to smell for several months.
Although anosmia caused by coronavirus is generally temporary, it’s advisable to seek treatment if you don’t regain your sense of smell soon after recovery.
Treatment for hyposmia or anosmia starts with figuring out the cause, so seeing an ENT specialist about these conditions is very important, starting with a thorough medical history and nasal exam. Diagnostic procedures may include nasal endoscopy, allergy testing, and a CT scan or MRI of the nose and sinuses.
Specialized smell tests can also help determine how much loss of smell you may have experienced.
Treatment of hyposmia and anosmia depends on its cause. When caused by a viral infection or an allergic reaction, it will usually clear up on its own. Over-the-counter decongestants may open the nasal passages and provide some relief. If the condition results from an infection, an antibiotic may be prescribed.
Surgery may be required for nasal polyps or other obstruction.
When it results from a particular medication, discontinuing the medication or substituting another may be done under a doctor’s supervision.
If the anosmia results from a disease, however, there may be no effective remedy. Smell training has helped in some cases.
On occasion, a person who has lost their sense of smell may regain it without any explanation as to why.
When the condition cannot be cured medically, particularly if it is the result of age, the patient can be taught to adapt. It is important for a patient with anosmia to have proper chemical detectors (gas and carbon monoxide) in the home, and to make sure food has not spoiled or become contaminated.