Discussion:
Olfactory dysfunction is known to affect the quality of life as patients
with olfactory dysfunction report difficulties with cooking, decreased
appetite and challenges with maintaining personal hygiene and social
relationships, fear of hazardous events (5) .
Post viral anosmia is one of the main reasons for smell dysfunction in
adults (40% of cases of anosmia). Common cold viruses or upper
respiratory tract infections are well known to cause post-infectious
smell loss. The previously described coronaviruses are assumed to
account for 10-15% of cases. So that, the COVID-19 virus supposed also
to be able to cause anosmia in infected patients and if it occurs, it is
not a specific finding (16) .
Olfactory dysfunction in COVID-19 patients, which can be the only
presenting symptom or with other symptoms, but its pathogenesis is still
not fully understood. It may result from viral-induced olfactory nerve
damage, local inflammation of the nasal passage, or both (17) .
In Kanjanaumporn et al. (3) study, short-term smell and taste
recovery rate was approximately 44-74%, which is higher than previous
reports of other post-viral olfactory dysfunction such as rhinovirus,
influenza, respiratory syncytial virus, and other coronaviruses.
Overall, 48.6–89% of COVID-19 patients with Olfactory dysfunction
experience complete remission or improvement after 4 weeks of follow-up(18) .
Le Bon et al. (19) in their systematic review showed that there
is no strong evidence to support using oral and topical corticosteroids
in patients with post-infection olfactory dysfunction. However other
studies like Kanjanaumporn et al.(3) stated that topical steroid treatment has improved the
chance of recovery in post-infectious olfactory dysfunction.
Our results support the results of Le Bon et al. (19) as no
statistically significant difference in improvement after topical
steroid usage combined with olfactory training in group B (60%) of
patients exhibited clinical improvement by the fouth week of treatement
compared to 56.6% in the control group A (olfactory training alone),
and this result matches with Abdealim et al. (20) and
Hintschich et al. (21) studies who suggested that using topical
mometasone furoate nasal spray in the treatment of post COVID- 19
anosmia offers no benefits over olfactory training.
In a retrospective cohort study
by Hummel et al. (22) revealed a benefit from intranasal
vitamin A 10000 IU per day in addition to olfactory training in the
treatment of post-infectious olfactory loss for two months of treatment.
Our resuts shows minor improvement rates in group C after combining
topical vitamin A with olfactory training 70 % of patients showed
clinical improvement by the end of fourth week compared to 56.6 % in
the control group A but this is not significantly differed from
olfactory training alone or with combined topical steroid usage after 4
weeks.
Our resuts shows inconclosive improvement rates in group D combined
topical theophylline with olfactory training (70%) of patients showed
clinical improvement by the end of fourth week compared to 56.6 % in
the control group A and this is also not superior than olfactory
training alone,combined topical steroid nor combined topical vitamin A
usage after 4 weeks, and this results matches the results of Gupta et
al. (23) and Lee et al. (24) studies.
By following the improvements in the study, all groups showed
significant improvements over the first three weeks of the study.
Comparing the smell scores between the studied groups, there was
superiority for the study group (group B) of topical mometasone nasal
spray, and (group C) topical vitamin A and (group D) topical
theophylline over the control group (group A) olfactory training alone
as the comparison of smell scores between all groups after 1 week, 2
weeks and 3 weeks of treatment, showed statistically significant
differences between groups, (P-values were
<0.001*) but no final significant difference between smell
scores between groups after the end of the fourth week
(p-value= 0.6) .
Regarding the duration of
anosmia/hyposmia and the recovery rates, there was a statistically
significant difference as the average time for complete recovery in
group B was 25.7 ± 9.20 days and group C was 24.8± 6.67 days and in
group D was 23.5± 7.13 days compared to 28.97 ± 4.29 days in the control
group A (P = 0.02*) . These results show that intranasal
vitamin A application and topical usage of theophylline help to shorten
the duration of post-COVID-19 anosmia/hyposmia.
Our study revealed no significant association between age, sex ,place of
management, severity of COVID-19 illness, obesity and the duration of
COVID-19 illness with smell scores and the duration of anosmia/hyposmia
in the studied groups but showed a high significant association between
other prognostic factors as; diabetes
(P-Value=<0.001***) , hypertension
(P-Value=<0.001***) , smoking
(P-Value=<0.001***) , and asthma
(P-Value=<0.001***) and full recovery within 4
weeks. We found a significant positive correlation between asthma and
both smell scores after 4 weeks and duration of anosmia/hyposmia
p-values were 0.01* and 0.03* respectively.
These results as regards the prognostic factors differ from
Esquinas-Requena et al. (25) , who confirmed that the only
prognostic factor of persistent olfactory/taste dysfunction in COVID-19
patients was the absence of fever as they studied the prognostic factors
during the period of COVID-19 illness, not after patient recovery.
Conclusion :
This study suggests that combining the usage of topical mometasone
furoate or topical vitamin A or intranasal theophylline with olfactory
training shortens the duration of post-COVID- 19 anosmia/hyposmia but
offers no superiority regarding smell scores over olfactory training
alone after 4 weeks.
Age, sex, place of management, severity of COVID-19 illness, obesity and
the duration of COVID-19 illness can be rolled out as discriminative
prognostic factors affecting the duration of anosmia but diabetes,
hypertension, smoking and asthma can affect the full recovery within
four weeks.