Treatment modalities for post-COVID-19 anosmia and hyposmia: a systematic review




COVID-19; SARS-COV-2; Anosmia; Hyposmia; Treatment.


Objective: To analyze the main treatment strategies for post-COVID-19 anosmia and hyposmia. Methods: Systematic review guided by PRISMA. The studies were searched between February and September 2021, in the electronic data sources of Pubmed, Cochrane (CENTRAL), LitCOVID and BVS. Inclusion criteria were clinical trials published from December 2019 to September 2021, on patients with maintenance of post-COVID-19 olfactory disorders, and the main existing treatment strategies were analyzed. Exclusion criteria were studies published before December 2019, performed in patients under 18 years of age and other types of study designs. Risk of bias analysis was performed using the ROB 2.0 tool for randomized clinical trials, and ROBINS-I for non-randomized trials. Results: Five articles were selected. A total of 237 patients with maintenance of post-COVID-19 olfactory disorders were evaluated. The follow-up of the patients' olfactory function ranged from a minimum of 3 weeks to a maximum of 10 weeks. The treatment modalities that demonstrated the greatest benefits to the olfactory function of these patients were corticosteroids and olfactory training. Conclusion: Treatment for post-COVID-19 anosmia and hyposmia should be started two weeks after the onset of olfactory symptoms. The use of corticosteroids and the practice of olfactory training are the treatment modalities that presented the best evidence regarding the recovery of olfactory function. Other less conventional modalities lack more robust evidence and cannot yet be recommended.


Abdelalim, A. A., Mohamady, A. A., Elsayed, R. A., Elawady, M. A., & Ghallab, A. F. (2021). Corticosteroid nasal spray for recovery of smell sensation in COVID-19 patients: A randomized controlled trial. American Journal of Otolaryngology, 42(2), 102884

ABORL-CCF - 4a Nota de Orientação aos médicos otorrinolaringologistas sobre COVID-19. (n.d.).

Croy, I., Nordin, S., & Hummel, T. (2014). Olfactory Disorders and Quality of Life—An Updated Review. Chemical Senses, 39(3), 185–194.

D’Ascanio, L., Vitelli, F., Cingolani, C., Maranzano, M., Brenner, M. J., & Stadio, A. D. I. (2021). Randomized clinical trial “olfactory dysfunction after COVID-19: Olfactory rehabilitation therapy vs. intervention treatment with Palmitoylethanolamide and Luteolin”: Preliminary results. European Review for Medical and Pharmacological Sciences, 25(11),

Hopkins, C., Alanin, M., Philpott, C., Harries, P., Whitcroft, K., Qureishi, A., Anari, S., Ramakrishnan, Y., Sama, A., & Davies, E. (2021). Management of new onset loss of sense of smell during the COVID‐19 pandemic ‐ BRS Consensus Guidelines. Clinical Otolaryngology, 46(1), 16–22.

Hura, N., Xie, D. X., Choby, G. W., Schlosser, R. J., Orlov, C. P., Seal, S. M., & Rowan, N. R. (2020). Treatment of post‐viral olfactory dysfunction: an evidence‐based review with recommendations. International Forum of Allergy & Rhinology, 10(9), 1065–1086.

KL, W., & T, H. (2019). Clinical Diagnosis and Current Management Strategies for Olfactory Dysfunction: A Review. JAMA Otolaryngology-- Head & Neck Surgery, 145(9), 846–853.

Kasiri H, N, R., E, S., M, G., & S, F. (2021). Mometasone furoate nasal spray in the treatment of patients with COVID-19 olfactory dysfunction: A randomized, double blind clinical trial. International Immunopharmacology, 98.

Kumar, B. Nirmal, C. H. (2020). Loss of sense of smell as marker of COVID-19 infection. ENT UK The Royal College Of Surgeons Of England, 2.

Le Bon, S.-D. Horoi, M., Konopnicki, D., Lechien, J. R., Pisarski, N., & Prunier, L. (2021). Efficacy and safety of oral corticosteroids and olfactory training in the management of COVID-19-related loss of smell. Eur Arch Otorhinolaryngol.

Lechien, J. R., Chiesa-Estomba, C. M., De Siati, D. R., Horoi, M., Le Bon, S. D., Rodriguez, A., Dequanter, D., Blecic, S., El Afia, F., Distinguin, L., Chekkoury-Idrissi, Y., Hans, S., Delgado, I. L., Calvo-Henriquez, C., Lavigne, P., Falanga, C., Barillari, M. R., Cammaroto, G., Khalife, M., … Saussez, S. (2020). Olfactory and gustatory dysfunctions as a clinical presentation of mild-to-moderate forms of the coronavirus disease (COVID-19): a multicenter European study. Eur Arch Otorhinolaryngol, 277(8), 2251–2261.

Lee, Y., Min, P., Lee, S., & Kim, S.-W. (2020). Prevalence and Duration of Acute Loss of Smell or Taste in COVID-19 Patients. Journal of Korean Medical Science, 35(18).

Mao, L., Jin, H., Wang, M., Hu, Y., Chen, S., He, Q., Chang, J., Hong, C., Zhou, Y., Wang, D., Miao, X., Li, Y., & Hu, B. (2020). Neurologic Manifestations of Hospitalized Patients With Coronavirus Disease 2019 in Wuhan, China. JAMA Neurology, 77(6), 683–690.

McGuinness, L. A., & Higgins, J. P. T. (2020). Risk-of-bias VISualization (robvis): An R package and Shiny web app for visualizing risk-of-bias assessments. Research Synthesis Methods

Page, M. J., McKenzie, J. E., Bossuyt, P. M., Boutron, I., Hoffmann, T. C., Mulrow, C. D., Shamseer, L., Tetzlaff, J. M., Akl, E. A., Brennan, S. E., Chou, R., Glanville, J., Grimshaw, J. M., Hróbjartsson, A., Lalu, M. M., Li, T., Loder, E. W., Mayo-Wilson, E., McDonald, S., & Moher, D. (2021). The PRISMA 2020 statement: An updated guideline for reporting systematic reviews. The BMJ, 372.

Rayyan – Intelligent Systematic Review. (n.d.).

Risk of Bias 2 (RoB 2) tool | Cochrane Methods. (n.d.).

ROBINS-I tool | Cochrane Methods. (n.d.).

Santos, C. M. D. C., Pimenta, C. A. D. M., & Nobre, M. R. C. (2007). A estratégia PICO para a construção da pergunta de pesquisa e busca de evidências. In Revista Latino-Americana de Enfermagem 15(3), 508–511.

T, M., K, I., T, I., M, K., K, K., Y, M., T, O., H, S., M, S., K, T., A, F., Y, M., S, F., & Y, K. (2019). Clinical practice guidelines for the management of olfactory dysfunction - Secondary publication. Auris, Nasus, Larynx, 46(5), 653–662.

Vaira, L. A., Hopkins, C., Petrocelli, M., Lechien, J. R., Cutrupi, S., Salzano, G., Chiesa-Estomba, C. M., Saussez, S., De Riu, G., Cutrupi, S., De Riu, G., Hopkins, C., Lechien, J. R., Petrocelli, M., Salzano, G., Saussez, S., & Vaira, L. A. (2020). Efficacy of corticosteroid therapy in the treatment of long- lasting olfactory disorders in COVID-19 patients. Rhinology, 59(1), 21–25.

Whitcroft, K. L., & Hummel, T. (2020). Olfactory Dysfunction in COVID-19: Diagnosis and Management. JAMA, 323(24), 2512–2514.

WHO Coronavirus (COVID-19) Dashboard | WHO Coronavirus (COVID-19) Dashboard With Vaccination Data. (n.d.).

Wu, Z., & McGoogan, J. M. (2020). Characteristics of and Important Lessons from the Coronavirus Disease 2019 (COVID-19) Outbreak in China: Summary of a Report of 72314 Cases from the Chinese Center for Disease Control and Prevention. JAMA - Journal of the American Medical Association, 323(13), 1239–1242.



How to Cite

CARVALHO, I. N. V.; MARAMBAIA, P. P. . Treatment modalities for post-COVID-19 anosmia and hyposmia: a systematic review. Research, Society and Development, [S. l.], v. 11, n. 6, p. e36911629101, 2022. DOI: 10.33448/rsd-v11i6.29101. Disponível em: Acesso em: 20 jun. 2024.



Health Sciences