{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T02:27:18Z","timestamp":1760149638434,"version":"build-2065373602"},"reference-count":51,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2023,8,22]],"date-time":"2023-08-22T00:00:00Z","timestamp":1692662400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Medicina"],"abstract":"<jats:p>Background and Objectives: Hypo\/anosmia is a characteristic symptom of COVID-19 infection. The aim of this study is to investigate the time of smell recovery and to identify a possible order of perception recovery of different odors in COVID-19 patients. Materials and Methods: A prospective observational study was conducted on not hospitalized COVID-19 patients, selected according to eligible criteria. The study was approved by the Ethical Committee. A questionnaire formulated by our team was submitted to patients in order to know the duration of the hypo\/anosmia and hypo\/ageusia and the order of odor recovery: vanillin (mixed olfactory\/gustatory substances), phenyl ethyl alcohol (rosewater) (pure olfactory substances), eucalyptol (mixed olfactory\/trigeminal substances), and eugenol (mixed olfactory\/trigeminal\/gustatory substances). Results: 181 patients were included. Hypo\/ageusia and hypo\/anosmia lasted on average 10.25 (\u00b18.26) and 12.8 (\u00b18.80) days, respectively. The most frequent odor recovery sequence was: (1) phenyl ethyl alcohol; (2) eucalyptol; (3) vanillin; and (4) eugenol. In COVID-19 patients, hypo\/anosmia occurs more often in women and at a young age. Conclusions: This preliminary investigation highlighted novel data: there is a chronological order in perception recovery of different olfactory substances and, therefore, in the restoration of the various sensitive nerve pathways involved in the sense of smell.<\/jats:p>","DOI":"10.3390\/medicina59091511","type":"journal-article","created":{"date-parts":[[2023,8,23]],"date-time":"2023-08-23T10:28:05Z","timestamp":1692786485000},"page":"1511","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Hyposmia in COVID-19: Temporal Recovery of Smell: A Preliminary Study"],"prefix":"10.3390","volume":"59","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1940-5281","authenticated-orcid":false,"given":"Barbara","family":"Verro","sequence":"first","affiliation":[{"name":"Division of Otorhinolaryngology, Department of Biomedicine, Neuroscience and Advanced Diagnostic, University of Palermo, 90127 Palermo, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Giulia","family":"Vivoli","sequence":"additional","affiliation":[{"name":"Division of Plastic, Reconstructive, Microvascular and Aesthetic Surgery, Department of Maternal-Infant and Adult Surgical Medical Sciences, University of Modena and Reggio Emilia, 41121 Modena, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1072-0736","authenticated-orcid":false,"given":"Carmelo","family":"Saraniti","sequence":"additional","affiliation":[{"name":"Division of Otorhinolaryngology, Department of Biomedicine, Neuroscience and Advanced Diagnostic, University of Palermo, 90127 Palermo, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,8,22]]},"reference":[{"key":"ref_1","unstructured":"World Health Organization (2021, February 13). WHO Director-General\u2019s Opening Remarks at the Media Briefing on COVID-19. Available online: https:\/\/www.who.int\/director-general\/speeches\/detail\/who-director-general-s-opening-remarks-at-the-media-briefing-on-covid-19-11-january-2021."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"103001","DOI":"10.1016\/j.amjoto.2021.103001","article-title":"Quality of life and safety impact of COVID-19 associated smell and taste disturbances","volume":"42","author":"Coelho","year":"2021","journal-title":"Am. J. Otolaryngol."},{"key":"ref_3","unstructured":"World Health Organization (2021, February 13). WHO Director-General\u2019s Opening Remarks at the Media Briefing on COVID-19. Available online: https:\/\/www.who.int\/director-general\/speeches\/detail\/who-director-general-s-opening-remarks-at-the-media-briefing-on-covid-19---11-march-2020."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"102581","DOI":"10.1016\/j.amjoto.2020.102581","article-title":"COVID-19 and anosmia: A review based on up-to-date knowledge","volume":"41","author":"Meng","year":"2020","journal-title":"Am. J. Otolaryngol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2251","DOI":"10.1007\/s00405-020-05965-1","article-title":"Olfactory and gustatory dysfunctions as a clinical presentation of mild-to-moderate forms of the coronavirus disease (COVID-19): A multicenter European study","volume":"277","author":"Lechien","year":"2020","journal-title":"Eur. Arch. Otorhinolaryngol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"299","DOI":"10.4193\/Rhin20.114","article-title":"Isolated sudden onset anosmia in COVID-19 infection. A novel syndrome?","volume":"58","author":"Gane","year":"2020","journal-title":"Rhinology"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Marchese-Ragona, R., Ottaviano, G., Nicolai, P., Vianello, A., and Carecchio, M. (2020). Sudden hyposmia as a prevalent symptom of COVID-19 infection. MedRxiv.","DOI":"10.1101\/2020.04.06.20045393"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"582","DOI":"10.1177\/1073858420956905","article-title":"Anosmia in COVID-19: Underlying Mechanisms and Assessment of an Olfactory Route to Brain Infection","volume":"27","author":"Butowt","year":"2021","journal-title":"Neuroscientist"},{"key":"ref_9","unstructured":"Centers for Disease Control and Prevention (2021, February 13). Symptoms of Coronavirus, Available online: https:\/\/www.cdc.gov\/coronavirus\/2019-ncov\/symptoms-testing\/symptoms.html."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"114","DOI":"10.1177\/0194599820929185","article-title":"Olfactory Dysfunction and Sinonasal Symptomatology in COVID-19: Prevalence, Severity, Timing, and Associated Characteristics","volume":"163","author":"Speth","year":"2020","journal-title":"Otolaryngol. Head Neck Surg."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"512","DOI":"10.1177\/0194599820954825","article-title":"Chemosensory Dysfunction in COVID-19: Prevalences, Recovery Rates, and Clinical Associations on a Large Brazilian Sample","volume":"164","author":"Fornazieri","year":"2021","journal-title":"Otolaryngol. Head Neck Surg."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"132","DOI":"10.1177\/0194599820922992","article-title":"COVID-19 Anosmia Reporting Tool: Initial Findings","volume":"163","author":"Kaye","year":"2020","journal-title":"Otolaryngol. Head Neck Surg."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1016\/j.anl.2021.07.007","article-title":"The prevalence of olfactory and gustatory dysfunction in COVID-19\u2014A systematic review","volume":"49","author":"Wu","year":"2022","journal-title":"Auris Nasus Larynx"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"473","DOI":"10.1177\/0194599820931820","article-title":"Taste and Smell Impairment in COVID-19: An AAO-HNS Anosmia Reporting Tool-Based Comparative Study","volume":"163","author":"Sayin","year":"2020","journal-title":"Otolaryngol. Head Neck Surg."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1038\/s41368-020-0074-x","article-title":"High expression of ACE2 receptor of 2019-nCoV on the epithelial cells of oral mucosa","volume":"20","author":"Xu","year":"2020","journal-title":"Int. J. Oral Sci."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"436","DOI":"10.1016\/j.medmal.2020.04.006","article-title":"Features of anosmia in COVID-19","volume":"50","author":"Klopfenstein","year":"2020","journal-title":"Med. Mal. Infect."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1093\/chemse\/bjn068","article-title":"Odor Localization and Sniffing","volume":"34","author":"Frasnelli","year":"2009","journal-title":"Chem. Senses"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"102","DOI":"10.1016\/j.neulet.2010.04.074","article-title":"Localisation of unilateral nasal stimuli across sensory systems","volume":"478","author":"Frasnelli","year":"2010","journal-title":"Neurosci. Lett."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"914","DOI":"10.1111\/coa.13620","article-title":"Is loss of sense of smell a diagnostic marker in COVID-19: A systematic review and meta-analysis","volume":"45","author":"Rocke","year":"2020","journal-title":"Clin. Otolaryngol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1621","DOI":"10.1016\/j.mayocp.2020.05.030","article-title":"Smell and Taste Dysfunction in Patients With COVID-19: A Systematic Review and Meta-analysis","volume":"95","author":"Agyeman","year":"2020","journal-title":"Mayo Clin. Proc."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"889","DOI":"10.1093\/cid\/ciaa330","article-title":"Self-reported Olfactory and Taste Disorders in Patients with Severe Acute Respiratory Coronavirus 2 Infection: A Cross-sectional Study","volume":"71","author":"Giacomelli","year":"2020","journal-title":"Clin. Infect. Dis."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1570","DOI":"10.1002\/hed.26228","article-title":"Validation of a self-administered olfactory and gustatory test for the remotely evaluation of COVID-19 patients in home quarantine","volume":"42","author":"Vaira","year":"2020","journal-title":"Head Neck"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"438","DOI":"10.1017\/S1049023X20000837","article-title":"An Insight into the Sex Differences in COVID-19 Patients: What are the Possible Causes?","volume":"35","author":"Sadoughi","year":"2020","journal-title":"Prehosp. Disaster Med."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"335","DOI":"10.1111\/joim.13089","article-title":"COVID-19 Task Force of YO-IFOS. Clinical and epidemiological characteristics of 1420 European patients with mild-to-moderate coronavirus disease 2019","volume":"288","author":"Lechien","year":"2020","journal-title":"J. Intern. Med."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"809","DOI":"10.1177\/0194599820920649","article-title":"Otolaryngology Providers Must Be Alert for Patients with Mild and Asymptomatic COVID-19","volume":"162","author":"Cheng","year":"2020","journal-title":"Otolaryngol. Head Neck Surg."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"3795","DOI":"10.1021\/acschemneuro.1c00477","article-title":"Mechanism of Anosmia Caused by Symptoms of COVID-19 and Emerging Treatments","volume":"12","author":"Najafloo","year":"2021","journal-title":"ACS Chem. Neurosci."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"2427","DOI":"10.1001\/jama.2020.8707","article-title":"Nasal Gene Expression of Angiotensin-Converting Enzyme 2 in Children and Adults","volume":"323","author":"Bunyavanich","year":"2020","journal-title":"JAMA"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"880","DOI":"10.1038\/s42003-021-02410-9","article-title":"Age-dependent appearance of SARS-CoV-2 entry sites in mouse chemosensory systems reflects COVID-19 anosmia-ageusia symptoms","volume":"4","author":"Lopes","year":"2021","journal-title":"Commun. Biol."},{"key":"ref_29","first-page":"207","article-title":"A follow-up on quantitative and qualitative olfactory dysfunction and other symptoms in patients recovering from COVID-19 smell loss","volume":"60","author":"Ohla","year":"2022","journal-title":"Rhinology"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"4122","DOI":"10.1128\/JVI.02232-10","article-title":"Evidence that TMPRSS2 activates the severe acute respiratory syndrome coronavirus spike protein for membrane fusion and reduces viral control by the humoral immune response","volume":"85","author":"Glowacka","year":"2011","journal-title":"J. Virol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"102474","DOI":"10.1016\/j.amjoto.2020.102474","article-title":"Upper airway symptoms in coronavirus disease 2019 (COVID-19)","volume":"41","author":"Lovato","year":"2020","journal-title":"Am. J. Otolaryngol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"2262","DOI":"10.1093\/cid\/ciaa525","article-title":"Olfactory and Gustatory Dysfunction in Coronavirus Disease 2019 (COVID-19)","volume":"71","author":"Luers","year":"2020","journal-title":"Clin. Infect. Dis."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"873","DOI":"10.1093\/bib\/bbaa168","article-title":"The Cellular basis of the loss of smell in 2019-nCoV-infected individuals","volume":"22","author":"Gupta","year":"2021","journal-title":"Brief Bioinform."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"4795","DOI":"10.7150\/ijbs.73485","article-title":"Revealing the mystery of persistent smell loss in Long COVID patients","volume":"18","author":"Park","year":"2022","journal-title":"Int. J. Biol. Sci."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"135694","DOI":"10.1016\/j.neulet.2021.135694","article-title":"Smell and taste disorders in COVID-19: From pathogenesis to clinical features and outcomes","volume":"748","author":"Mastrangelo","year":"2021","journal-title":"Neurosci. Lett."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"eabc5801","DOI":"10.1126\/sciadv.abc5801","article-title":"Non-neuronal expression of SARS-CoV-2 entry genes in the olfactory system suggests mechanisms underlying COVID-19-associated anosmia","volume":"6","author":"Brann","year":"2020","journal-title":"Sci. Adv."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1097\/MOO.0000000000000783","article-title":"COVID-19 related olfactory dysfunction","volume":"30","author":"Karamali","year":"2022","journal-title":"Curr. Opin. Otolaryngol. Head Neck Surg."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"579","DOI":"10.1016\/j.bbi.2020.06.032","article-title":"Massive transient damage of the olfactory epithelium associated with infection of sustentacular cells by SARS-CoV-2 in golden Syrian hamsters","volume":"89","author":"Bryche","year":"2020","journal-title":"Brain Behav. Immun."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"806","DOI":"10.1002\/alr.22579","article-title":"Association of chemosensory dysfunction and COVID-19 in patients presenting with influenza-like symptoms","volume":"10","author":"Yan","year":"2020","journal-title":"Int. Forum Allergy Rhinol."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"611","DOI":"10.1093\/chemse\/bjy049","article-title":"Olfactory and Trigeminal Systems Interact in the Periphery","volume":"43","author":"Tremblay","year":"2018","journal-title":"Chem. Senses"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"26","DOI":"10.1186\/s40463-020-00423-8","article-title":"Early recovery following new onset anosmia during the COVID-19 pandemic\u2014An observational cohort study","volume":"49","author":"Hopkins","year":"2020","journal-title":"J. Otolaryngol. Head Neck Surg."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"2337","DOI":"10.1111\/odi.14300","article-title":"Chemosensory loss in COVID-19","volume":"28","author":"Xu","year":"2022","journal-title":"Oral Dis."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"748","DOI":"10.1111\/odi.13371","article-title":"Is gustatory impairment the first report of an oral manifestation in COVID-19?","volume":"27","author":"Vinayachandran","year":"2021","journal-title":"Oral Dis."},{"key":"ref_44","unstructured":"Obiefuna, S., and Donohoe, C. (2020). StatPearls, StatPearls Publishing. Available online: https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK554522\/."},{"key":"ref_45","unstructured":"American Academy of Otolaryngology-Head and Neck Surgery (AAO-NHS) (2020, April 20). Anosmia Reporting Tool. Available online: https:\/\/www.entnet.org\/content\/reporting-tool-patients-anosmia-related-covid-19."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"821","DOI":"10.1002\/alr.22592","article-title":"Self-reported olfactory loss associates with outpatient clinical course in COVID-19","volume":"10","author":"Yan","year":"2020","journal-title":"Int. Forum Allergy Rhinol."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"686","DOI":"10.1177\/1945892420930954","article-title":"Prevalence and Recovery from Olfactory and Gustatory Dysfunctions in COVID-19 Infection: A Prospective Multicenter Study","volume":"34","author":"Chary","year":"2020","journal-title":"Am. J. Rhinol. Allergy"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"3519","DOI":"10.1007\/s00405-020-06102-8","article-title":"Olfactory and gustatory dysfunctions in 100 patients hospitalized for COVID-19: Sex differences and recovery time in real-life","volume":"277","author":"Meini","year":"2020","journal-title":"Eur. Arch. Otorhinolaryngol."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"e439","DOI":"10.1097\/SCS.0000000000007245","article-title":"Subjective Smell Assessment as An Office-based Rapid Procedure In COVID-19 Era","volume":"32","author":"Azab","year":"2021","journal-title":"J. Craniofac. Surg."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"346","DOI":"10.18176\/jiaci.0595","article-title":"Smell and Taste Dysfunction in COVID-19 Is Associated with Younger Age in Ambulatory Settings: A Multicenter Cross-Sectional Study","volume":"30","author":"Villarreal","year":"2020","journal-title":"J. Investig. Allergol. Clin. Immunol."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"103068","DOI":"10.1016\/j.amjoto.2021.103068","article-title":"Characteristics of COVID-19 smell and taste dysfunction in hospitalized patients","volume":"42","author":"Husain","year":"2021","journal-title":"Am. J. Otolaryngol."}],"container-title":["Medicina"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1648-9144\/59\/9\/1511\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T20:39:56Z","timestamp":1760128796000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1648-9144\/59\/9\/1511"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,8,22]]},"references-count":51,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2023,9]]}},"alternative-id":["medicina59091511"],"URL":"https:\/\/doi.org\/10.3390\/medicina59091511","relation":{},"ISSN":["1648-9144"],"issn-type":[{"type":"electronic","value":"1648-9144"}],"subject":[],"published":{"date-parts":[[2023,8,22]]}}}