CME INDIA Presentation by Dr N K Singh, Admin, CME INDIA.

Could anosmia and loss of taste be a COVID pointer?

What is the observational experience of anosmia? Could it be a pointer as mild disease? What is the average time to recovery? Are there some measures to treat it?

Let us see, what CME INDIA members opine:

Dr Anu Jain, Ambala Cant: I have seen 3-4 such patients. One of my patients had fever for 2 days, but anosmia lasted almost 2 weeks. Other patient had both taste and smell loss, recovered within 1 week.

Dr Noni G Singha, Consultant Physician, Debrugarh, Assam: I have not observed anosmia but being reported, some change in taste occurs but no loss of sweet and salty. Difficult to comment it as a pointer to COVID as people do not come forward for testing even some doctors are not sending patient for testing (reason not known).

Looks a milder form with less body ache, malaise, less tiredness/ weakness, hardly any change in health as compared to pre COVID, less cough, no shortness of breath. All severity markers normal or mildly raised at diagnosis and on retesting after 2-days interval like NPR, CRP, s ferritin, LDH, Blood sugar. It takes 6-7 days (mild symptomatic).

Treat usually with proper hydration, balanced diet, rest, good sleep, oral hygiene, steam inhalation, prophylactic antibiotic, Ivermectin 12mg (OD 3 days).

Dr Arvind Ojha, Consultant Physician, Kolkata: Not very common in hospitalised patient, but anorexia is common. I have not observed more than 10% in non-hospitalised patient. Yes, agree, points to mild disease. Usually in 2nd week, it improves. No specific treatment probably.

Dr Subhankar Chatterjee, MD, Med, Ranchi: Anosmia and loss of taste are very typical of COVID infection. I have seen nearly 30% patients who had anosmia as their complaint.  In my community prevalence is nearly 10%. Young, female, tribal patients without comorbidity (particularly Dm, HTN, CKD) tend to have asymptomatic to mild disease. It takes 5 to 7 days to improve. Yes, it is a pointer to mild disease – mainly close observation, isolation, symptomatic treatment with pcm, antihistamine. Doxycycline, azithromycin may be added. Still very dubious evidence regarding hcqs, ivermectin. Favipiravir-questionable benefit. Treat comorbidity aggressively.

For moderate to severe disease – LMWH is a game changer. Dexamethasone to be added, particularly if there are radiological manifestations. Be cautious about blood sugar level. Remdesivir may be added. Plasma therapy, mechanical ventilator and ecmo for severe diseases.

Dr Surendra Kr Goyal, Consultant physician, Kota: I am sharing experience of six of one family members. All four-female had Anosmia and change of taste. It did not involve male members. One male was completely asymptomatic, one young female had no other symptoms. In two young females, these symptoms appeared on first day two middle aged female had these symptoms after 5 days. All had symptoms for three to four weeks. One recovered completely in three weeks. Three had return of symptoms in form of some change in taste and feeling of abnormal smell even after three months of illness. In my experience, it is predominately in females, mild course is the rule, symptoms last much longer.

Dr Bijay Patni, Diabetologist, Kolkata: My observation: Loss of taste and loss of smell in good numbers (roughly – 30% – 35%) – variable recovery from 7- 45 days. All developed mild illness. No specific management needed.

Dr Anil Motta, Sr Consultant, Dept. of Med, Max Hospital, Delhi: Anosmia in my observation about 2 to 3 %. {With confirmed RTPCR}. Otherwise would be more about 8 to 10 %. Prevalence. They developed: Fever; myalgias; asthenia & mild throat irritation. No worsening. RTPCR positive. Usually 10 days to improve; though had good relief of symptoms in 3 to 5 days. I treated with: a) Doxycycline BD 10 days) Ivermectin 12 mg BD 3 days) HCQS 400 BD day 1& 200 BD for 7 days d) Vit C 500mg BD; Zinc 75 OD; Calcium BD e) Betadine gargles.

Dr N K Singh, (Admin), Dhanbad: I have experience of 30 patients who got anosmia and ageusia. It appeared 2 to 3 days after onset of first symptoms which was nasal stiffness, throat irritation and mild cough and fever. I do treat with current trend of management of mild cases (Includes Ivermectin). All recovered well. Most of them recovered within 3 weeks. Prevalence is about 35%.

Dr Sangita Kamath, Consultant Physician, TMH, Jamshedpur: I have come across patient complaining of loss of taste. But is it true ageusia or medicine induced, not known. I have seen 5 patients so far complain of loss of smell & taste. Sometimes get bad smell too, but it returns within 2 to 3 weeks. Average time to partial recovery about 6 days. But weakness persisting for about 2 weeks. Some people develop joint pains, diarrhoea… No specific measures, only symptomatic.

Dr Sanjeev R Pathak, Diabetologist, Ahmedabad: By now we have treated/came across >400 patients with COVID. About 10-15% young patients (age below 30) & 5-7% older patients present with ANOSMIA. Disease remains very mild in these patients Recovery is very quick (2-4 days). Markers remain mostly normal. We generally give only doxycycline plus Ivermectin &don’t give FAVIPIRAVIR to these patients. None of these patients required hospitalisation. Very few develop pneumonia on HRCT.

Dr Akash Singh, Consultant physician, Baroda:

Many patients who comes for admission have these symptoms, may be 2 to3 days prior 2. Prevalence is I think 15-20% of the patients. Majority of the patients are stable if this is the predominant symptom. However, if it is associated with other symptoms like fever body ache cough dyspnea, patient may land up with moderate to severe disease too. Hence anosmia as a sole complaint or with associated mild complaints are the ones who are going to do well. Solo-anosmia: Time to recovery, which I have observed is 3 to 5 days. No specific measures available. Anosmia may take weeks to get rectified I ask them not to take inhalation of strong vapors, very hot steam inhalation and be mild on their mucosa.

CME INDIA Learning Points:

  • In the beginning of the pandemic, the most common COVID-19 symptoms include fever (43.8% on initial presentation and 88.7% during hospitalization), cough (67.8%), nasal congestion (4.8%), nausea or vomiting (5.0%), and diarrhea (3.8%) as per Chinese study. Some suspicion about atypical presentations as anosmia or ageusia were suspected.
  • Today scenario has totally changed and warrants awareness of a possible COVID-19 infection must be raised in patients with the sole presentation of anosmia and ageusia. Some patients have also reported dysgeusia, referring to a change in taste in the mouth. Loss of smell, or anosmia, is one of the earliest and most commonly reported symptoms of COVID-19. Some COVID-19 patients, however, experience anosmia without any nasal obstruction.
  • With these symptoms, you can greet your patient as lucky as course is going to be mild. This extra attention is sometimes a game-changer for patient care and safety. As anosmia emerge as a symptom of COVID-19, this tells more people to self-isolate, even in absence of other symptoms, to prevent further spread of the virus. This is good news that encouraging rates of recovery without any treatment has been reported. Many patients report return of sense of smell within 7-14 days.
  • Anosmia and Ageusia as the only indicators of COVID-19 has been reported worldwide. Studies suggest it better predicts the disease than other well-known symptoms such as fever and cough. With paucity of testing facility and heavy load on health care system, it is being coined that take it as COVID positive, isolate and treat symptomatically.
  • Gustatory dysfunction is also reported to be common in COVID-19, and is thought to occur in 42% of patients in one study. (This usually reflects loss of flavour perception as a function of smell, rather than true taste disturbance. Asking patients if they can tell if the food is salty, sweet, or bitter may help to differentiate taste which is a function of gustation, as opposed to flavour which is a function of retro nasal olfaction).
  • The length of loss of smell is not related to how infectious patient is, tell your patient not to worry that he or she may be passing on the infection to others later on, even if sense of smell has not recovered.

How it happens? Have a look at this:

Loss of smell in COVID
(Courtesy Anosmia in COVID-19: A Bumpy Road to Establishing a Cellular Mechanism ACS Chem. Neurosci. 2020, 11, 2152−2155)
  • Sustentacular cells (SUS) are entering the game. SUS infection results in a rapid loss of neuronal cilia containing the olfactory receptors. Inflammatory processes might be working. No definite mechanisms has been validated.
  • Sustentacular cells (SUSs) express ACE2 and are infected first. Impairment of SUS negatively affects olfactory receptor neurons (ORNs), leading to the inhibition of odor perception cascade (double lines).
  • Simultaneously, rapid immune response is induced in a subset of ORNs and in microvillar cells (MVCs). This leads to activation of lymphocytes and macrophages and their infiltration into the OE as well as secretion of proinflammatory cytokines.
  • It is not currently known whether SARS-CoV-2 passes to ORNs as these neurons do not express ACE2 (question mark).
  • The possibility of infection of progenitor cells requires examination, since these cells express ACE2 and are in close contact with SUS cells (question mark). Stem cell infection may potentially explain why a small fraction of COVID-19 patients experience long-term dysosmia.

How it is managed, as per scientific guidelines:

  • Topical corticosteroid drops (fluticasone nasule or betamethasone drops) in patients with loss of smell lasting longer than two weeks has been advocated. Topical corticosteroid sprays to patients with associated nasal obstruction.
  • Always personalised patient centred decisions are needed. Consider a short course of oral steroids in patients with a persistent loss of smell in those patients with persistent loss of sense of smell following COVID-19 after at least two weeks since diagnosis. In persisting loss of smell cases Olfactory training” a self-management strategy (involves a regular programme of using strong odours or essential oils to trigger recovery of the olfactory system.) is being tried although evidence is incomplete.
  • Very small study raised hope that omega-3 fatty acid intake might help.

CME INDIA Tail Piece:

What you need to know?


  • Half of patients with COVID-19 may lose sense of smell; guidance states that a new change or loss in sense of smell should prompt a period of self-isolation.
  • 9 in 10 patients can expect substantial improvement in their sense of smell within four weeks.
  • Most patients with loss of smell do not require further investigations or referral, although their COVID-19 status should be established if possible.
  • Treatment involves reassurance, olfactory training, safety advice, and topical corticosteroids—but oral prednisolone should be avoided where acute COVID-19 infection is suspected.


  1. Anosmia in COVID-19: A Bumpy Road to Establishing a Cellular Mechanism ACS Chem. Neurosci. 2020, 11, 2152−2155
  2. Non-neuronal expression of SARS-CoV-2 entry genes in the olfactory system suggests mechanisms underlying COVID-19-associated anosmia. Science Advances, July 24, 2020; DOI: 10.1126/sciadv.abc5801
  3. Tong JY, et al. The prevalence of olfactory and gustatory dysfunction in COVID-19 patients: a systematic review and meta-analysis. Otolaryngol Head Neck Surg2020;163:3-11. doi:10.1177/0194599820926473. pmid:32369429
  4. Borsetto D, et al. Self-reported alteration of sense of smell or taste in patients with COVID-19: a systematic review and meta-analysis on 3563 patients. Rhinology2020. doi:10.4193/Rhin20.185. pmid:32626853

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