Terapia de rehabilitación olfatoria en pacientes con síndrome pos-COVID-19 / Olfactory rehabilitation therapy in patients with post-COVID-19 syndrome

El olfato desempeña una función importante en el desarrollo diario de la vida de las personas. Sus alteraciones pueden ser cualitativas (disosmias, parosmias o fantosmias) y cuantitativas (hiposmia o anosmia). Estas alteraciones pueden deberse por enfermedades rinosinusales, neurodegenerativas o infecciones respiratorias como el resfriado común, la gripe y también el SARS-CoV-2, el agente causal del COVID-19. En relación a esta etiología, su fisiopatología no es del todo clara y la anosmia es poco distinguible clínicamente del resto de las infecciones virales, con una duración variable desde ocho días hasta más de cuatro semanas, en cuyo caso se denomina síndrome pos-COVID-19 o COVID prolongado. Este cuadro se caracteriza por la presencia de síntomas que se desarrollan durante la enfermedad aguda por COVID-19,y que persisten durante más de cuatro semanas, sin explicación por un diagnóstico alternativo. El autor de este artículo realiza una revisión de la literatura médica a partir de un caso clínico con el fin de identificar y resumir la evidencia disponible sobre la terapia de rehabilitación olfatoria. (AU)

Sense of smell plays an important role in the daily development of people's lives. Its alterations can be both qualitative (dysosmias, parosmias, or phantosmias) and quantitative (hyposmia or anosmia). These alterations may be due to rhinosi-nusal diseases, neurodegenerative diseases, and respiratory infections such as common cold, influenza, and SARS-CoV-2,causative agent of COVID-19. In relation to this etiology, its pathophysiology is not entirely clear, and anosmia is clinically indistinguishable from the rest of the viral infections, with a variable duration ranging from eight days to more than four weeks, in which case it would be called post COVID- 19 syndrome or prolonged COVID. This condition is characterized by the presence of symptoms that develop during acute COVID-19 illness and persist for more than four weeks without an explanation by an alternative diagnosis.The author of this article carries out a review of the medical literature based on a clinical case in order to identify and summarize the available evidence on olfactory rehabilitation therapy. (AU)

Olfactory Training and Visual Stimulation Assisted by a Web Application for Patients With Persistent Olfactory Dysfunction After SARS-CoV-2 Infection: Observational Study.

BACKGROUND: Persistent olfactory dysfunction is a significant complication of SARS-CoV-2 infection. Olfactory training involving aromatic oils has been recommended to improve olfactory recovery, but quantitative data are missing. OBJECTIVE: We aimed to quantify the benefit of olfactory training and visual stimulation assisted by a dedicated web application for patients who experienced olfactory dysfunction for ≥1 month. METHODS: We performed an observational, real-life, data-based study on a cohort of patients who experienced at least 1 month of persistent olfactory dysfunction between January 30 and March 26, 2021. An analysis was performed after a mean olfactory training time of 4 weeks, and at least 500 patients were assessable for primary outcome assessment. Participants exposed themselves twice daily to odors from 4 high-concentration oils and visual stimulation assisted by a dedicated web application. Improvement was defined as a 2-point increase on a 10-point, self-assessed olfactory visual analogue scale. RESULTS: In total, 548 patients were assessable for primary outcome assessment. The mean baseline, self-assessed olfactory score was 1.9 (SD 1.7), and this increased to 4.6 (SD 2.8) after a mean olfactory training time of 27.7 days (SD 17.2). Olfactory training was associated with at least a 2-point increase in 64.2% (352/548) of patients. The rate of patients' olfactory improvement was higher for patients who trained for more than 28 days than that rate for patients who trained for less than 28 days (73.3% vs 59%; P=.002). The time to olfactory improvement was 8 days faster for patients with hyposmia compared to the time to improvement for patients with anosmia (P<.001). This benefit was observed regardless of the duration of the olfactory dysfunction. CONCLUSIONS: Olfactory training and visual stimulation assisted by a dedicated web application was associated with significant improvement in olfaction, especially after 28 days of olfactory training.