Otolaryngology-Head and Neck Surgery
COVID-19 Related Issues
During the COVID-19 pandemic, it has become clear that one of the common symptoms of this viral infection is the loss of smell and/or taste. In fact, this has been reported as the only symptom in some patients. Studies on the loss of smell related to this viral infection have shown smell loss to be a complaint in a large majority of patients. When using a smell test to assess smell loss, one study found a deficiency in 95% of patients. Often, the loss of smell is noticed as a loss of taste. True taste is the ability to appreciate food as salty, sweet, bitter, sour, or savory (umami). In some patients there have been reports of true taste loss, although it occurs in a much lower percent of patients. In most cases, when the sense of smell is lost, the patient notices a loss in appreciating the flavor of food. Flavor is a combination of smell, taste, texture, temperature and everything else involved with eating. When the sense of smell is absent, food has a very bland flavor and becomes a noticeable part of COVID-19 related smell loss.
In most cases, patients will experience the onset of nasal congestion, cough, or sore throat prior to the loss of smell. However, in many cases, smell loss occurs before any other symptom and may be the only symptom. It is important to recognize that during the COVID-19 pandemic, any sudden loss of sense of smell and/or taste should be considered a result of COVID-19 infection. If sudden smell loss is experienced, you should quarantine immediately and contact your primary care physician to arrange COVID-19 testing.
Duration of Smell Loss
Luckily, smell loss from COVID-19 is usually brief in duration, typically lasting 2-3 weeks. In some cases, however, patients may experience a lingering loss of smell or only partial recovery. We believe in these cases there is more extensive damage to the nerves in the nose that detect odors. If that occurs, the nerves need to be replaced with new nerves. This can take months to several years to occur, however we are seeing a more rapid recovery in COVID-19 related smell loss than other previously identified viral smell losses. It’s difficult to predict how long it will take for each person with COVID-19 related smell loss to recover since each person is different. In some cases, patients have not experienced a full return after 10 months. However, this is not unusual for non-COVID-19 related post-viral smell loss, and in some cases patients can have permanent loss. We are still learning whether COVID-19 patients with lingering smell loss follow a similar pattern.
The long period of recovery is a result of the time it takes for cells in the nasal cavity to divide and make new nerve cells. These nerve cells then need to grow connections that travel through the skull to the brain. They then need to make appropriate connections with nerves in the brain to make sense of what we are smelling. For this reason, recovery can be a very slow process with small incremental improvements over time.
A common feature being reported in patients with COVID-19 related smell loss is the occurrence of smell distortions or parosmia. This is the experience of smelling something you are familiar with and it not smelling like it used to. In many cases, the smell is bad and can have an effect on flavor of food. In many cases, this occurs with only certain smells. In other cases, it occurs with all odors. Typically, this is temporary, but it can be discouraging and last for weeks to months. It is often considered a sign of regeneration of the nerves used for smell. It may be a result of the “faulty wiring” that initially occurs when the axon processes from the nose land on the wrong targets in the brain. For COVID-19, we are finding this to be a more common symptom than prior forms of post-viral smell loss. Usually, as the sense of smell improves, the smell distortion decreases and more odors are correctly experienced.
As stated above, if someone experiences new onset smell/taste loss during the pandemic, it should be considered a result of COVID-19 infection until testing proves otherwise. Patients should seek advice from their physician and quarantine for the recommended time period for COVID-19 infection. The sense of smell typically returns as the patient recovers from the illness.
If after three weeks, the sense of smell remains absent, patients should be seen by an otolaryngologist or ear, nose and thorat (ENT) surgeon to assess for other possible causes of smell loss. There are no proven medical treatments for COVID-19 or other viral related smell losses. In some cases, steroid pills or topical nasal steroids are used by physicians in attempt to decrease inflammation and help restore the sense of smell. The use of medication for this purpose should be determined after discussing the associated risks and benefits with your doctor.
One form of therapy that has shown benefit to those with post-viral smell loss in multiple research studies is termed olfactory training. This treatment involves smelling four odors (lemon, cloves, eucalyptus, and rose), for about 10-15 seconds each, with a slight rest between every sample. This is repeated for a second time later in the day and performed every day for 3 months. A modified version has been shown to add further benefit and suggests switching the odors to a different set of four odors for another 3 months, and then again switching to a third set of four odors for the last 3 months.
If patients have smell loss it is important to recognize that they are compromised in their ability to detect hazardous odors in the environment. Inability to detect smoke from a fire can be dangerous, and smoke detectors need to be checked for proper functioning. Natural gas appliances need to be checked for leaks given the lack of ability to detect natural gas in the home. Foods that have extended beyond their expiration date should be thrown out since patients without smell cannot detect the odor from rotten food.
- Any patients with new onset smell and/or taste loss during the pandemic should immediately self-quarantine and should be considered COVID-19 positive until testing proves otherwise.
- Patients with persistent COVID-19 related smell loss should be seen by an otolaryngologist (ENT) or sinus specialist to rule out other forms of smell loss. These physicians can also recommend possible medical treatments if warranted.
- Olfactory training is a safe and often effective form of therapy for post-viral smell loss.
- While patients experience smell loss, they need to be aware of hazards in the environment they could encounter when odors are unrecognized.
Approximately 20% of all hospitalized patients with COVID-19 in the U.S. require ventilator support. An emerging role for otolaryngologists in the coming weeks and months is the management laryngeal complications of COVID-19.
Respiratory failure requiring intubation and tracheostomy is a common consequence of severe COVID-19 infection and laryngeal complications including damage to the vocal cords, granulomas, laryngotracheal stenosis, and swallowing impairment are well known sequelae of intubation.
In the laryngology clinics at Mass Eye and Ear, we reported abnormal laryngeal findings in 100% of patients who had COVID-19 undergoing laryngoscopy and roughly half with significant laryngeal pathology requiring surgical intervention. If not treated immediately, these problems can lead to lasting complications.
Given the infectious potential of COVID-19 through aerosol transmission, best practice guidelines for nasopharyngoscopy examinations were published by a multi-institutional group of Otolaryngology-Head and Neck Surgery (OHNS) providers, spearheaded by Dr. Gregory Randolph, director of the Thyroid Division at Mass Eye and Ear.
These recommendations include understanding the infectious transmission risk in the outpatient clinic based on prevalence, testing reliability, access to personal protective equipment, clinic procedural airborne and droplet potential.
Specific recommendations include:
- Symptoms and contact screening
- Use of personal protective equipment (PPE)
- Environmental and engineering mitigation strategies
- Procedural risk reduction
- Source control
COVID-19 and social distancing regulations have impacted gatherings and venues where singing has taken place. Singing has also been linked to some high-transmission events because COVID-19 is transmitted through aerosols, and singers are potentially at greater risk of transmitting the virus during performances and rehearsals.
Common sense recommendations, such as rehearsing alone, remotely or outside, wearing personal protective equipment and incorporating testing may reduce risk of transmission.
Dr. Phillip C. Song, director of the Division of Laryngology at Mass Eye and Ear, answers some questions that many group singers and performers may have during this unprecedented time in our blog, Focus.
There is insufficient evidence to link facial palsy to COVID-19 vaccine. We strongly urge all those eligible to receive the vaccine.
The Facial Nerve Center agrees with the statement from the FDA, “The observed frequency of reported Bell’s palsy in the vaccine group is consistent with the expected background rate in the general population, and there is no clear basis upon which to conclude a causal relationship at this time.”
Read the full statement