Prevalence of clinical manifestation and past medical history of COVID-19 patients and its association with olfactory and gustatory dysfunction
The most common clinical manifestations of the patients were fever and myalgia (both with 51.8% prevalence), dyspnea (39.7%), fatigue (21.6%), dry cough (20.7%), anorexia (20.7%), and asthenia (18.7%). Among the COVID-19 patients, 18% and 17.4% had diabetes mellitus and hypertension (Table1). The mean duration of patients’ admission was 10 ±3.1 days.
Among COVID-19 patients, 103(33.7%) experienced olfactory-gustatory dysfunctions; of which 25.2 % had isolated hyposmia, 16.5% had isolated hypogeusia 13.6% isolated ageusia, and 6.8% isolated anosmia. 16.5% had hyposmia and hypogeusia, 13.6% hyposmia and ageusia, 7.8% anosmia and dysgeusia and 1.9% had anosmia and ageusia.
When comparing two groups with and without olfactory dysfunction, positive family history, and presence of postnasal discharge were statistically significant different. When comparing patients with and without gustatory dysfunction, sex, positive family history, cheek pain, presence of postnasal discharge, use of mask and overuse of sanitizers were statistically significantly different between the two groups. Most patients (more than 60 %) reported loss of sweat and salty taste more than other tastes. 19 (6.6%) and 14 (4.6%) patients reported olfactory and gustatory dysfunction as the first presentation, respectively.
Numerical scaling of olfactory and gustatory dysfunction in patients with olfactory-gustatory manifestations of COVID-19
Among patients with olfactory manifestations of COVID-19, numerical scaling of olfactory dysfunction varied from 1 to 7 out of 10. A noticeable proportion of the patients (17.8%) gave a score of 0 or 1 to their olfactory sensation at the time of infection. 18.8% of the patients had a score of 2 and 3 while the majority (33.7%), gave a 4. Further, 7% of the patients had a score between 5 to 7.
Among patients with gustatory manifestations of COVID-19, numerical scaling of gustatory varied from 1 to 8 out of 10. 20% of the patients gave a score of 0 and 1 to their gustatory sensation at the time of infection. Overall, 10.7% of the patients had a score of 2 and 3 while 18.7% of the patients had a score of 4. The score mentioned most frequently was 5 with prevalence of 25.3%. Lastly, 25.3% of the patients gave a score between 6 to 8 to their gustatory sensation at the time of COVID-19 infection.
Prevalence of clinical manifestations before and after the onset of olfactory and gustatory dysfunction
In terms of olfactory dysfunction, headache, dyspnea, vomiting, diarrhea and sneezing all happened before the onset of olfactory dysfunction in 5.3%, 18.7%, 2.7%, 1.3% and 2.7% of the patients with COVID-19, respectively. Symptoms including sore throat, pneumonia, myalgia, weakness, cough and fever were present either before or after, but predominantly before onset of olfactory dysfunction. Facial fullness and sinus pain was only present after the onset of olfactory dysfunction in 1.3% of the patients with COVID-19.
In terms of gustatory dysfunction, headache, facial fullness and sinus pain, vomiting, diarrhea and sneezing all happened before onset of gustatory dysfunction in 5.9%, 1%, 5%, 1% and 1% of the patients. Moreover, symptoms such as dyspnea, pneumonia, sore throat, myalgia, weakness, cough and fever were reported after or predominantly before the onset of gustatory dysfunction.
Recovery time of olfactory and gustatory dysfunction and its association with clinical manifestations and past medical history
Recovery time of olfactory dysfunction happened more than 10 days among 54.5% of the patients with olfactory manifestations of COVID-19. 21.8% of the patients had not yet recovered from olfactory dysfunction after two months post-infection.
Recovery time from gustatory dysfunction happened more than 10 days among 56.9% of the patients with gustatory manifestations of COVID-19. Recovery from gustatory dysfunction had not occurred in 20.1% of the patients before two months.
Time of recovery from olfactory dysfunction was found to be significantly associated with presence of fatigue (p-value=0.043), dyspnea (p-value=0.032), and pneumonia (p-value=0.046) (Table2). Time of recovery from gustatory dysfunction demonstrated a statistically significant association with presence of fatigue (p-value=0.046) and dyspnea (p-value=0.038) (Table3).