journal article Feb 07, 2026

Long-Term Olfactory Dysfunction in COVID-19 Patients: A Systematic Review

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References
46
[1]
COVID-19 cases. (2025). Accessed. December 8, 2025: https://data.who.int/dashboards/covid19/cases.
[2]
Rahmati M, Udeh R, Kang J, et al.. Long-term sequelae of COVID-19: a systematic review and meta-analysis of symptoms 3 years post-SARS-CoV-2 infection. J Med Virol. 2025, 97:10.1002/jmv.70429 10.1002/jmv.70429
[3]
Post COVID-19 condition (long COVID). (2025). Accessed. December 8, 2025: https://www.who.int/europe/news-room/fact-sheets/item/post-covid-19-condition.
[4]
Saniasiaya J, Prepageran N. Impact of olfactory dysfunction on quality of life in coronavirus disease 2019 patients: a systematic review. J Laryngol Otol. 2021, 135:947-52. 10.1017/S0022215121002279 10.1017/s0022215121002279
[5]
GRADE: an emerging consensus on rating quality of evidence and strength of recommendations

Gordon H Guyatt, Andrew D Oxman, Gunn E Vist et al.

BMJ 2008 10.1136/bmj.39489.470347.ad
[6]
Boldes T, Ritter A, Soudry E, Diker D, Reifen E, Yosefof E. The long-term effect of COVID-19 infection on olfaction and taste; a prospective analysis. Eur Arch Otorhinolaryngol. 2024, 281:6001-7. 10.1007/s00405-024-08827-2 10.1007/s00405-024-08827-2
[7]
Boscolo-Rizzo P, Tofanelli M, Zanelli E, Gardenal N, Tirelli G. COVID-19-related quantitative and qualitative olfactory and gustatory dysfunction: long-term prevalence and recovery rate. ORL J Otorhinolaryngol Relat Spec. 2023, 85:67-71. 10.1159/000525861 10.1159/000525861
[8]
Callejón-Leblic MA, Martín-Jiménez DI, Moreno-Luna R, et al.. Analysis of prevalence and predictive factors of long-lasting olfactory and gustatory dysfunction in COVID-19 patients. Life (Basel). 2022, 12:10.3390/life12081256 10.3390/life12081256
[9]
Ciofalo A, Cavaliere C, Masieri S, et al.. Long-term subjective and objective assessment of smell and taste in COVID-19. Cells. 2022, 11:10.3390/cells11050788 10.3390/cells11050788
[10]
Fernandez IJ, Molinari G, Federici G, et al.. Delayed recovery from severe acute respiratory syndrome coronavirus-2 related anosmia predicts incomplete olfactory restoration. J Laryngol Otol. 2022, 136:237-42. 10.1017/S0022215121004047 10.1017/s0022215121004047
[11]
Ferreli F, Gaino F, Russo E, et al.. Long-standing gustatory and olfactory dysfunction in COVID-19 patients: a prospective study. Eur Arch Otorhinolaryngol. 2022, 279:4633-40. 10.1007/s00405-022-07428-1 10.1007/s00405-022-07428-1
[12]
Kalak G, Jarjou'i A, Bohadana A, et al.. Prevalence and persistence of symptoms in adult COVID-19 survivors 3 and 18 months after discharge from hospital or corona hotels. J Clin Med. 2022, 11:10.3390/jcm11247413 10.3390/jcm11247413
[13]
Lamb MM, DeHority K, Russel SM, et al.. Characteristics of olfactory dysfunction in patients with long-haul COVID-19. Rhinol Online. 2023, 6:30-7.
[14]
Liu X, Chiu SH, Tan CY, Chua AJ. Long-term recovery from COVID-19 olfactory and gustatory dysfunction: a longitudinal study. Singapore Med J. 2024, 10.4103/singaporemedj.SMJ-2022-174 10.4103/singaporemedj.smj-2022-174
[15]
McWilliams MP, Coelho DH, Reiter ER, Costanzo RM. Recovery from COVID-19 smell loss: two-years of follow up. Am J Otolaryngol. 2022, 43:10.1016/j.amjoto.2022.103607 10.1016/j.amjoto.2022.103607
[16]
Otte MS, Bork ML, Zimmermann PH, Klussmann JP, Luers JC. Persisting olfactory dysfunction improves in patients 6 months after COVID-19 disease. Acta Otolaryngol. 2021, 141:626-9. 10.1080/00016489.2021.1905178 10.1080/00016489.2021.1905178
[17]
Perez O, Santibañez M, Rasines L, Castillo JM, Aginagalde-Llorente AH. Long-term patient symptoms and quality of life in adults after COVID-19: a real life study. Open Respir Arch. 2024, 6:10.1016/j.opresp.2024.100336 10.1016/j.opresp.2024.100336
[18]
Petrocelli M, Cutrupi S, Salzano G, et al.. Six-month smell and taste recovery rates in coronavirus disease 2019 patients: a prospective psychophysical study. J Laryngol Otol. 2021, 135:436-41. 10.1017/S002221512100116X 10.1017/s002221512100116x
[19]
Prem B, Liu DT, Besser G, et al.. Long-lasting olfactory dysfunction in COVID-19 patients. Eur Arch Otorhinolaryngol. 2022, 279:3485-92. 10.1007/s00405-021-07153-1 10.1007/s00405-021-07153-1
[20]
Rass V, Beer R, Schiefecker AJ, et al.. Neurological outcomes 1 year after COVID-19 diagnosis: a prospective longitudinal cohort study. Eur J Neurol. 2022, 29:1685-96. 10.1111/ene.15307 10.1111/ene.15307
[21]
Riestra-Ayora J, Yanes-Diaz J, Esteban-Sanchez J, Vaduva C, Molina-Quiros C, Larran-Jimenez A, Martin-Sanz E. Long-term follow-up of olfactory and gustatory dysfunction in COVID-19: 6 months case-control study of health workers. Eur Arch Otorhinolaryngol. 2021, 278:4831-7. 10.1007/s00405-021-06764-y 10.1007/s00405-021-06764-y
[22]
Larijani MS, Ashrafian F, Amiri FB, et al.. Characterization of long COVID-19 manifestations and its associated factors: a prospective cohort study from Iran. Microb Pathog. 2022, 169:10.1016/j.micpath.2022.105618 10.1016/j.micpath.2022.105618
[23]
Schambeck SE, Crowell CS, Wagner KI, et al.. Phantosmia, parosmia, and dysgeusia are prolonged and late-onset symptoms of COVID-19. J Clin Med. 2021, 10:10.3390/jcm10225266 10.3390/jcm10225266
[24]
Turk B, Aybal A, Salepci E, Dizdar SK, Turgut S. What Is the long-term findings of olfactory and taste loss due to COVID-19?. Sisli Etfal Hastan Tip Bul. 2022, 56:466-72. 10.14744/SEMB.2022.56492 10.14744/semb.2022.56492
[25]
Wang N, Yang MB, Yang PY, et al.. A case series of olfactory dysfunction in imported COVID-19 patients: a 12-month follow-up study. Biomed Environ Sci. 2022, 35:402-11. 10.3967/bes2022.056 10.3967/bes2022.056
[26]
Zhu Y, Cao M, Zheng P, Shen W. Residual olfactory dysfunction in coronavirus disease 2019 patients after long term recovery. J Clin Neurosci. 2021, 93:31-5. 10.1016/j.jocn.2021.07.050 10.1016/j.jocn.2021.07.050
[27]
Wu D, Wang VY, Chen YH, Ku CH, Wang PC. The prevalence of olfactory and gustatory dysfunction in COVID-19 - a systematic review. Auris Nasus Larynx. 2022, 49:165-75. 10.1016/j.anl.2021.07.007 10.1016/j.anl.2021.07.007
[28]
Thaweethai T, Jolley SE, Karlson EW, et al.. Development of a definition of postacute sequelae of SARS-CoV-2 infection. JAMA. 2023, 329:1934-46. 10.1001/jama.2023.8823 10.1001/jama.2023.8823
[29]
Otte MS, Haehner A, Bork ML, Klussmann JP, Luers JC, Hummel T. Impact of COVID-19-mediated olfactory loss on quality of life. ORL J Otorhinolaryngol Relat Spec. 2023, 85:1-6. 10.1159/000523893 10.1159/000523893
[30]
Tong JY, Wong A, Zhu D, Fastenberg JH, Tham T. The prevalence of olfactory and gustatory dysfunction in COVID-19 patients: a systematic review and meta-analysis. Otolaryngol Head Neck Surg. 2020, 163:3-11. 10.1177/0194599820926473 10.1177/0194599820926473
[31]
Ahmad S, Sohail A, Chishti MA, Rehman MA, Farooq H. How common are taste and smell abnormalities in COVID-19? A systematic review and meta-analysis. J Taibah Univ Med Sci. 2022, 17:174-85. 10.1016/j.jtumed.2021.10.009 10.1016/j.jtumed.2021.10.009
[32]
Saniasiaya J, Islam MA, Abdullah B. Prevalence of olfactory dysfunction in coronavirus disease 2019 (COVID-19): a meta-analysis of 27,492 patients. Laryngoscope. 2021, 131:865-78. 10.1002/lary.29286 10.1002/lary.29286
[33]
Dias M, Shaida Z, Haloob N, Hopkins C. Recovery rates and long-term olfactory dysfunction following COVID-19 infection. World J Otorhinolaryngol Head Neck Surg. 2024, 10:121-8. 10.1002/wjo2.163 10.1002/wjo2.163
[34]
von Bartheld CS, Wang L. Prevalence of olfactory dysfunction with the Omicron variant of SARS-CoV-2: a systematic review and meta-analysis. Cells. 2023, 12:10.3390/cells12030430 10.3390/cells12030430
[35]
Eligulashvili A, Gordon M, Lee JS, et al.. Long-term outcomes of hospitalized patients with SARS-CoV-2/COVID-19 with and without neurological involvement: 3-year follow-up assessment. PLoS Med. 2024, 21:10.1371/journal.pmed.1004263 10.1371/journal.pmed.1004263
[36]
Akerlund A, Bende M, Murphy C. Olfactory threshold and nasal mucosal changes in experimentally induced common cold. Acta Otolaryngol. 1995, 115:88-92. 10.3109/00016489509133353 10.3109/00016489509133353
[37]
Lechien JR, Chiesa-Estomba CM, De Siati DR, et al.. 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. 2020, 277:2251-61. 10.1007/s00405-020-05965-1 10.1007/s00405-020-05965-1
[38]
Eliezer M, Hamel AL, Houdart E, et al.. Loss of smell in patients with COVID-19: MRI data reveal a transient edema of the olfactory clefts. Neurology. 2020, 95:3145-52. 10.1212/WNL.0000000000010806 10.1212/wnl.0000000000010806
[39]
Butowt R, von Bartheld CS. Anosmia in COVID-19: underlying mechanisms and assessment of an olfactory route to brain infection. Neuroscientist. 2021, 27:582-603. 10.1177/1073858420956905 10.1177/1073858420956905
[40]
Park JW, Wang X, Xu RH. Revealing the mystery of persistent smell loss in long COVID patients. Int J Biol Sci. 2022, 18:4795-808. 10.7150/ijbs.73485 10.7150/ijbs.73485
[41]
Zazhytska M, Kodra A, Hoagland DA, et al.. Non-cell-autonomous disruption of nuclear architecture as a potential cause of COVID-19-induced anosmia. Cell. 2022, 185:1052-64. 10.1016/j.cell.2022.01.024 10.1016/j.cell.2022.01.024
[42]
Wu Y, Xu X, Chen Z, et al.. Nervous system involvement after infection with COVID-19 and other coronaviruses. Brain Behav Immun. 2020, 87:18-22. 10.1016/j.bbi.2020.03.031 10.1016/j.bbi.2020.03.031
[43]
Asvapoositkul V, Samuthpongtorn J, Aeumjaturapat S, Snidvongs K, Chusakul S, Seresirikachorn K, Kanjanaumporn J. Therapeutic options of post-COVID-19 related olfactory dysfunction: a systematic review and meta-analysis. Rhinology. 2023, 61:2-11. 10.4193/Rhin22.221 10.4193/rhin22.221
[44]
Chen CH, Shih CF, Hummel T, Chao YT. Multidimensional benefits of olfactory training for chronic COVID-19-related olfactory dysfunction: a systematic review and meta-analysis. Rhinology. 2025, 63:431-40. 10.4193/Rhin24.355 10.4193/rhin24.355
[45]
Wang JY, Pao JB, Lee CH, Wang JY, Lee MC, Wu TT. Corticosteroids for COVID-19-induced olfactory dysfunction: a comprehensive systematic review and meta-analysis of randomized controlled trials. PLoS One. 2023, 18:10.1371/journal.pone.0289172 10.1371/journal.pone.0289172
[46]
Capra AP, Ardizzone A, Crupi L, Calapai F, Campolo M, Cuzzocrea S, Esposito E. Efficacy of palmitoylethanolamide and luteolin association on post-COVID olfactory dysfunction: a systematic review and meta-analysis of clinical studies. Biomedicines. 2023, 11:10.3390/biomedicines11082189 10.3390/biomedicines11082189
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Published
Feb 07, 2026
Cite This Article
Artemis Zarkadi, Michail Katotomichelakis, Konstantinos Chaidas (2026). Long-Term Olfactory Dysfunction in COVID-19 Patients: A Systematic Review. Cureus. https://doi.org/10.7759/cureus.103143
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