Our observations regarding olfactory disorders in COVID-19
Authors: Bezeha Bohdan 
Published: August 2022

Topicality: Despite a large number of patients and, accordingly, the large number of publications in the medical literature, numerous clinical manifestations of the disease due to COVID-19 have not yet been sufficiently studied. One of the leading symptoms of COVID-19 is impaired olfactory function, primarily anosmia. According to the literature, anosmia is noted in 30 to 60% of patients. It can be an early and sometimes the only characteristic symptom of the disease. Treatment of olfactory disorders is a difficult task. Therefore timely detection of disorders and early targeted therapy is of great medical and social importance.
Aim: to determine the features of the clinical manifestations of olfactory dysfunction in patients with COVID-19.
Materials and methods: An analysis of the clinical and instrumental examination of 53 pat ients with COVID-19 was carried out. In addition, an endoscopic examination of the nasal cavity was carried out using the workplace of an otorhinolaryngologist with the Mega Medical NET-1100 endovideo complex.
Results and their discussion: According to the analysis of survey data of 130 patients with the help of a particular questionnaire developed by us to determine sensory organ function disorders in patients with COVID-19, the majority of subjects (69.2% of cases – 90 patients) noted olfactory function disorders, mainly in the form of anosmia 25.4% (33 patients) or weakening of olfactory sensitivity by 22.3% (29 patients). However, in 21.5% (28 patients) of cases, the sense of smell or its enhancement was distorted. Mainly, smell impairment occurred in the first few days of the disease, and hearing was partially or wholly restored after recovery. However, in 26.2% - 34 patients, certain disorders persisted for 1-3 months after the illness, and in 15.3% - 20 patients, the sense of smell did not fully recover five months after recovery.
We examined 53 patients who became ill with COVID-19 and complained of impaired olfactory function, which persisted after recovery from 2 weeks to 1.5 months, mainly in the form of complete anosmia 34% (18 patients), weakening of olfactory function 26, 4% (14 patients) and distortion 39.6% (21 patients). In general, according to our observations, independent recovery (primarily partial) is observed in patients with COVID-19 within 2 to 6 months, and more often, it occurs with changes in sensitivity and distortions of the perception of some smells.
According to the endoscopic data, 54% of the examined had no visible signs of mucosal disorders. It was pink, hydrated, and without signs of inflammation, thinning, hypertrophy or oedema. In 13 patients (24.5%), there was an increase in the vascular pattern and moderate oedema. Seven patients (13.2%) showed signs of dryness and thinning of the mucous membrane, sometimes with crusts. Approximately 79.3% (42 patients) of the examined subjects had anatomical features that partially or significantly limited air access to the olfactory zone (upper nasal passage). In addition, 19 (35.8%) of the studied patients were diagnosed with marked curvature of the nasal septum, and 5 (9.4%) with allergic rhinitis.
Conclusions:
1. In the vast majority of cases, the disease with COVID-19 is accompanied, in addition to other symptoms, by damage to the olfactory analyser system.
2. Violat ion of smell with COVID-19 is usually observed immediately during the disease and, in some patients (in 25-30% of cases), persists for a long time after recovery.
3. Violations of the olfactory function in COVID-19 are manifested not only in the form of anosmia but also in the form of a decrease, exacerbation, or distortion of the sense of smell.
4. Violat ions of the olfactory function in COVID-19, which persist after clinical recovery, in most cases are not manifested by visible disorders of the mucous membrane of the olfactory zone of the nasal cavity.