Clinical features of patients who had two COVID-19 episodes: a European multicentre case series.

OBJECTIVE: To investigate the clinical features of patients who had two demonstrated coronavirus disease 2019 (COVID-19) episodes. METHODS: Data of patients with both COVID-19 episodes were recruited from 22 March to 27 December 2020. The following outcomes were studied: epidemiological, comorbidities, prevalence and severity of general and otolaryngological symptom, olfactory, aroma, and gustatory dysfunctions. A comparison between first and second episodes was performed. RESULTS: Forty-five patients reported having two confirmed COVID-19 episodes. The majority of patients had mild infections in both episodes. The second clinical episode was significantly similar to the first. The symptom duration of the second episode was shorter than the first. The occurrence of loss of smell was unpredictable from the first to the second episode. CONCLUSION: The recurrence of COVID-19 symptoms is associated with a similar clinical picture than the first episode in patients with initial mild-to-moderate COVID episode. The pathophysiological mechanisms underlying the development of second episode remain uncertain and may involve either true reinfection or virus reactivation from sanctuaries.

Prevalence and 6-month recovery of olfactory dysfunction: a multicentre study of 1363 COVID-19 patients.

OBJECTIVE: To investigate prevalence and recovery of olfactory dysfunction (OD) in COVID-19 patients according to the disease severity. METHODS: From 22 March to 3 June 2020, 2581 COVID-19 patients were identified from 18 European hospitals. Epidemiological and clinical data were extracted at baseline and within the 2-month post-infection. RESULTS: The prevalence of OD was significantly higher in mild form (85.9%) compared with moderate-to-critical forms (4.5-6.9%; P = 0.001). Of the 1916 patients with OD, 1363 completed the evaluations (71.1%). A total of 328 patients (24.1%) did not subjectively recover olfaction 60 days after the onset of the dysfunction. The mean duration of self-reported OD was 21.6 ± 17.9 days. Objective olfactory evaluations identified hyposmia/anosmia in 54.7% and 36.6% of mild and moderate-to-critical forms, respectively (P = 0.001). At 60 days and 6 months, 15.3% and 4.7% of anosmic/hyposmic patients did not objectively recover olfaction, respectively. The higher baseline severity of objective olfactory evaluations was strongly predictive of persistent OD (P < 0.001). CONCLUSION: OD is more prevalent in mild COVID-19 forms than in moderate-to-critical forms. OD disappeared in 95% of patients regarding objective olfactory evaluations at 6 months.

Olfactory epithelium histopathological findings in long-term coronavirus disease 2019 related anosmia.

BACKGROUND: Olfactory dysfunction represents one of the most frequent symptoms of coronavirus disease 2019, affecting about 70 per cent of patients. However, the pathogenesis of the olfactory dysfunction in coronavirus disease 2019 has not yet been elucidated. CASE REPORT: This report presents the radiological and histopathological findings of a patient who presented with anosmia persisting for more than three months after infection with severe acute respiratory syndrome coronavirus-2. CONCLUSION: The biopsy demonstrated significant disruption of the olfactory epithelium. This shifts the focus away from invasion of the olfactory bulb and encourages further studies of treatments targeted at the surface epithelium.