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Inicio Medicina Clínica (English Edition) Subjective evaluation of smell and taste dysfunction in patients with mild COVID...
Journal Information
Vol. 156. Issue 2.
Pages 61-64 (January 2021)
Vol. 156. Issue 2.
Pages 61-64 (January 2021)
Brief report
DOI: 10.1016/j.medcle.2020.08.004
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Subjective evaluation of smell and taste dysfunction in patients with mild COVID-19 in Spain
Evaluación subjetiva de las alteraciones del olfato y del gusto en pacientes con afectación leve por COVID-19 en España
Elisabeth Ninchritz-Becerraa,b,
Corresponding author

Corresponding author.
, María Montserrat Soriano-Reixacha,b, Miguel Mayo-Yáneza,c, Christian Calvo-Henríqueza,d, Paula Martínez-Ruiz de Apodacaa,e, Carlos Saga-Gutiérreza, Pablo Parente-Ariasf, Itzhel María Villarealg, Jaime Viera-Artilesh, Daniel Poletti-Serafinii, Isam Alobidj, Tareck Ayada,k, Sven Sausseza,l, Jerome R. Lechiena,m, Carlos M. Chiesa-Estombaa,b
a Task Force COVID-19 of the Young-Otolaryngologists of the International Federations of Oto-rhino-laryngological Societies (YO-IFOS)
b Servicio de Otorrinolaringología, Hospital Universitario Donostia, San Sebastián, Guipúzcoa, Spain
c Servicio de Otorrinolaringología, Complexo Hospitalario Universitario A Coruña (CHUAC), EIDUS, A Coruña, Spain
d Servicio de Otorrinolaringología, Complejo Hospitalario Universitario de Santiago de Compostela, Santiago de Compostela, Spain
e Servicio de Otorrinolaringología, Hospital Universitario Doctor Peset, Valencia, Spain
f Servicio de Otorrinolaringología, Hospital Universitario Lucus Augusti, Lugo, Spain
g Servicio de Otorrinolaringología, Hospital Universitario de Fuenlabrada, Hospital La Milagrosa, Madrid, Spain
h Unidad de Rinología y Base de Cráneo, Servicio de Otorrinolaringología, Hospital Universitario Marqués de Valdecilla, Santander, Spain
i Servicio de Otorrinolaringología, Hospital General Universitario Gregorio Marañón, Servicio de Otorrinolaringología Hospital La Milagrosa, Madrid, Spain
j Unidad de Rinología y Base de Cráneo, Servicio de Otorrinolaringología, Hospital Clínic, Universidad de Barcelona, IDIBAPS, CIBERES, Barcelona, Spain
k Division of Otolaryngology-Head & Neck Surgery, Centre Hospitalier de l'Université de Montréal, Montreal, Canada
l Department of Human Anatomy and Experimental Oncology, Faculty of Medicine, UMONS Research Institute for Health Sciences and Technology, University of Mons (UMons), Mons, Belgium
m Department of Otolaryngology-Head & Neck Surgery, Foch Hospital, School of Medicine, UFR Simone Veil, Université Versailles Saint-Quentin-en-Yvelines (Paris Saclay University), Paris, France
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Figures (1)
Tables (2)
Table 1. Clinical and demographic variables.
Table 2. Multivariate analysis of characteristics associated with loss of smell and taste in patients affected by COVID-19.
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Additional material (1)

Has been described the loss of smell and taste as onset symptoms in SARS-CoV-2. The objective of this study was to investigate the prevalence in Spain.


Prospective study of COVID-19 confirmed patients through RT-PCR in Spain. Patients completed olfactory and gustatory questionnaires.


A total of 1043 patients with mild COVID-19 disease. The mean age was 39 ± 12 years. 826 patients (79.2%) described smell disorder, 662 (63.4%) as a total loss and 164 (15.7%) partial. 718 patients (68.8%) noticed some grade of taste dysfunction. There was a significant association between both disorders (p < 0.001). The olfactory dysfunction was the first symptom in 17.1%. The sQOD-NS scores were significantly lower in patients with a total loss compare to normosmic or hyposmic individuals (p = 0.001). Female were significantly more affected by olfactory and gustatory dysfunctions (p < 0.001). The early olfactory recover in 462 clinically cured patients was 315 (68.2%), during the first 4 weeks.


The sudden onset smell and/or taste dysfunction should be considered highly suspicious for COVID-19 infection.

Antecedentes y objetivo

En la infección por SARS-CoV-2 la pérdida repentina del olfato y/o gusto han sido descritas como síntomas iniciales. El objetivo principal de este estudio es conocer la prevalencia de estos síntomas en España.

Materiales y métodos

Estudio prospectivo de pacientes con COVID-19 confirmado mediante RT-PCR en España. Se utilizaron los cuestionarios traducidos y validados.


Un total de 1043 pacientes COVID-19 leve. Edad media de 39 ± 12 años. 826 pacientes (79,2%) refirieron algún grado de alteración del olfato, 662 (63,4%) pérdida total y 164 (15,7%) parcial. 718 pacientes (68,8%) notaron alteración del gusto. Hubo una asociación significativa entre ambos trastornos (p < 0,001). La disfunción olfatoria fue el síntoma inicial en el 17,1%. Las puntuaciones del sQOD-NS fueron significativamente menores en pacientes con una alteración total. Ambas alteraciones fueron proporcionalmente mayores en las mujeres (p < 0,001). De 462 pacientes clínicamente curados 315 (68,2%) recuperaron el olfato dentro de las primeras 4 semanas.


La alteración repentina del olfato y el gusto debería ser reconocida como un síntoma de alarma de posible infección por COVID-19.

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The clinical presentation of patients affected by COVID-19 in a mild-moderate way has consisted mainly of cough (46.6-83.3%), asthenia (63.3-72.9%), headache (60-71 %), anosmia (51.5-70.2%), nasal obstruction (58.6-67.8%) and taste dysfunctions (47.1-67.8%).1–3 Furthermore, the presence of comorbidities such as arterial hypertension, advanced age and obesity have been associated with a worse progression.

The main objective of this study was to investigate the prevalence of subjective smell (SSD) and taste (STD) dysfunction in patients with mild-moderate SARS-CoV-2 infection. The secondary objectives focused on evaluating the impact on quality of life resulting from these dysfunctions and the rate of recovery of both senses.

Patients and methods

This is a prospective study in which the patients included with mild-moderate COVID-19 responded to a questionnaire designed for the analysis of smell and/or taste dysfunction.

The inclusion and exclusion criteria used, as well as the clinical and/or subjective data, were obtained by completing an on-line questionnaire. These, as well as the study design are shown in Fig. 1Fig. 1. All patients were asked to complete a short version of the olfactory dysfunction questionnaire (sQOD-NS).4 The rest of the questions about smell and taste were obtained from the North American National Health and Nutrition questionnaire.5

Fig. 1.

The inclusion and exclusion criteria, as well as clinical and/or subjective data, were obtained through an on-line questionnaire.


The mean recovery of the sense of smell was evaluated between the days: 1–4; 5–8; 9–14 and >15. Referring to the studies that have shown that viral load drops significantly 14 days after the onset of symptoms.6

The Statistical Package for the Social Sciences (SPSS version 21.0; IBM Corp, Armonk, NY, USA) software was used to perform the statistical analyses. The normality contrast between the continuous variables was performed using the Shapiro-Wilk test. Potential associations between epidemiological, clinical, olfactory, and taste outcomes were evaluated by cross-tabulation between two variables (dichotomous or categorical variables) and the chi-square test. Incomplete responses were excluded from the analysis. Differences in the sQOD-NS in terms of olfactory dysfunctions between patients were analysed using the Kruskal-Wallis test. A multivariate logistic regression model was applied to estimate the association between smell and taste dysfunction with a group of independent variables (age, sex, symptoms, comorbidities). A value of p< 0.05 was determined to be statistically significant.


Of the total 1411 patients with positive RT-PCR for COVID-19 infection, 1043 patients completed the study. Regarding sex, 663 (63.6%) were women and 380 (36.4%) were men. The mean age was 39 ± 12 years (range 19−78). The most common comorbidities are listed in Table 1, Table 1. 42% of the patients were in the acute phase of the infection.

Table 1.

Clinical and demographic variables.

Variable  p 
Female  663  63.6  0.294 
Male  380  36.4   
Mean Age  39 ± 12 years (range 19−78),     
European  859  82.4   
Latin American  173  16.6   
North American  0.6   
North African  0.3   
Sub-Saharan Africa  0.2   
Diabetes mellitus  20  1.9  0.921 
Arterial hypertension  68  6.5  0.892 
WP or NP rhinosinusitis  22  2.1  0.339 
Autoimmune disease (SLE, RA, etc.)  36  3.5  0.066 
Hypothyroidism in treatment  59  5.7  0.535 
Hypothyroidism without treatment  0.6  0.671 
Allergic rhinitis  192  18.4  0.661 
Renal failure  11  1.1  0.902 
Liver failure  16  1.5  0.116 
COPD  0.8  0.947 
Asthma  63  0.454 
Cardiac pathology  20  1.9  0.076 
Neurodegenerative disease  0.9  0.917 
Depression  46  4.4  0.381 
Cancer in treatment  0.3  0.663 
Cancer pending treatment  0.2  0.095 
Extrinsic allergies (pollen, grass, etc.)  264  25.3  0.053 
Smoking habit
Non-smoker  914  87.6  0.337 
0-10 cigarettes-day  101  9.7  0.115 
11-20 cigarettes-day  26  2.5  0.077 
>20 cigarettes a day  0.2  0.965 
Symptoms associated with COVID-19
Fever > 38°  391  37.5  0.027 
Dry cough  570  54.7  0.038 
Loss of appetite  595  57  0.078 
Bronchial mucus-expectoration  207  19.8  0.087 
Arthralgia  517  49.6  0.998 
Myalgia  719  68.9  0.709 
Diarrhoea  419  40.2  0.009 
Abdominal pain  210  20.1  0.763 
Headache  782  75  0.540 
Mean time onset of disease/evaluation  10.4 ° ±  5.7 days (range 4-13)     

RA : rheumatoid arthritis; WP : with polyps; COPD : chronic obstructive pulmonary disease; SLE : systemic lupus erythematosus; NP : without polyps.

Regarding SSD, 826 patients (79.2%) described some type of loss related to the infection. Of these, 662 described their dysfunction as total and 164 as partial. Furthermore, 16.6% associated changes suggestive of dysosmia, and 18.2% phantosmia. SSD appeared before (17.1%), after (47.8%) or at the same time as the rest of the general and/or otolaryngological symptoms (23.9%).

The recovery rate of smell evaluated in 462 cured patients after 4 weeks revealed that 315 (68.2%) showed a partial or total recovery. 57.5% recovered olfactory function in the first 7 days after the resolution of the disease with an overall mean of 9 ± 6 days (range 5–29).

Regarding the impact of SSD on quality of life, patients who perceived a total loss of smell had a significantly lower score (sQOD-NS) compared to those individuals with a partial loss (p = 0.001) or who did not notice any dysfunction of smell (p = 0.001) (Appendix B supplementary material).

Regarding STD, 718 patients (68.8%) reported taste disorders. STD consisted of a reduced (48%) or distorted (22.9%) ability to perceive flavours. Of the 286 patients without taste dysfunction, 52 (5%) did not have olfactory dysfunction, while 194 (18.6%) had a total dysfunction of smell and 40 (3.8%) a partial one.

Multivariate analysis showed that women (OR = 0.924; 95% CI: 0.876–1.69) or those over 60 years of age (OR = 0.980; 95% CI: 0.723–1.113) had a higher risk of suffering from SSD or STD. In addition, a significant correlation between the presence of fever (OR = 0.981; 95% CI: 0.434–1.396) or headache (OR = 1,160; 95% CI: 0.917–1.313) and SSD or STD was observed. While we did not find a correlation between otolaryngological symptoms and the presence of comorbidities with the occurrence of sensory dysfunctions (Table 2).

Table 2.

Multivariate analysis of characteristics associated with loss of smell and taste in patients affected by COVID-19.

Variable  OR  95% confidence interval  p 
Sex (female)  0.924  0.876 to 1.369  0.020 
Age (> 60 years0.980  0.723 to 1.113  0.023 
Diabetes mellitus  0.460  −2.308 to 0.756  0.321 
Arterial hypertension  0.626  −1.290 to 0.852  0.263 
WP or NP rhinosinusitis  0.692  −0.054 to 1.035  0.163 
Autoimmune disease (SLE, RA, etc.)  0.659  −1.571 to 0.737  0.479 
Hypothyroidism in treatment  0.525  −0.333 to 0.777  0.273 
Hypothyroidism without treatment  0.173  −0.460 to 0.449  0.268 
Allergic rhinitis  0.331  −0.199 to 0.455  0.790 
Renal failure  0.243  −0.188 to 0.356  0.281 
Liver failure  1.317  −0.070 to 1.468  0.064 
COPD  0.722  −0.236 to 0.932  0.394 
Asthma  1.200  −0.587 to 1.952  0.642 
Cardiac pathology  0.930  −0.522 to 1.837  0.275 
Neurodegenerative disease  0.144  −0.528 to 0.658  0.144 
Depression  0.611  −0.360 to 1.314  0.264 
Extrinsic allergies (pollen, grass, etc.)  0.532  −0.032 to 0.885  0.068 
Smoker  0.371  −0.674 to 0.615  0.929 
Symptoms associated with COVID-19       
Fever > 38°  0.981  0.434 to 1.396  0.008 
Dry cough  1.202  −0.377 to 1.744  0.521 
Loss of appetite  0.482  −0.027 to 0.814  0.067 
Bronchial mucus-expectoration  0.978  −0.513 to 1.468  0.929 
Arthralgia  0.835  0.642 to 1.281  0.443 
Myalgia  1.038  0.449 to 1.524  0.123 
Diarrhoea  1.092  −0.321 to 1.497  0.673 
Abdominal pain  0.657  0.213 to 0.769  0.268 
Headache  1.160  0.917 to 1.313  0.021 
ENT symptoms       
Nasal Congestion  0.997  0.145 to 1.139  0.967 
Rhinorrhoea  0.816  0.376 to -1.031  0.531 
Postnasal drip  1.019  0.425 to 1.163  0.799 
MF  1.007  0.546 to 0.160  0.931 
CF pain  1.240  0.376 to 1.354  0.102 
Earache  0.909  0.681 to 0.990  0.311 
Dysphagia  0.972  0.431 to 1.174  0.781 
Dyspnoea  0.951  0.605 to 1.104  0.521 

RA: rheumatoid arthritis; WP : with polyps; COPD : chronic obstructive pulmonary disease; SLE : lupus erythematosus; OR : odds ratio; NP : without polyps.


After the expansion of SARS-CoV-2 in Europe, multiple authors have described the high incidence of SSD and STD in patients with COVID-19, even as the only clinical manifestation.7

Several studies have observed a high rate of recovery of smell within 1–2 weeks after the onset of anosmia or hyposmia, and a recovery of taste between the second and third week after the onset of ageusia or hypogeusia.6 As well as a higher prevalence of SSD and STD in women, young and with mild or asymptomatic symptoms.3

Identification and isolation of patients with SARS-CoV-2 is the most important strategy to slow the spread of the disease. Given the scarcity of diagnostic tests, it is important to determine which are the most common initial symptoms for early isolation. Within our population, we have especially investigated mild-moderate cases and we have confirmed the presence of anosmia or dysgeusia in a high percentage of patients.

We highlight as strengths of this study the size of the sample and the reproducibility of the questionnaire. Despite being a study with a reduced follow-up time (maximum one month), we consider that the findings are valuable insofar as they can define early prevention attitudes while helping to define lines of work for future studies. While the main limitation of this study corresponds to the use of a questionnaire by telematic means, which we can tend to underestimate the olfactory threshold.


At present, multiple publications have found a relationship between SARS-CoV-2 infection (COVID-19) and smell and/or taste dysfunction. These data suggest that there is a significant association between viral infection and olfactory or gustatory dysfunction, and that this information could help in the early diagnosis of SARS-CoV-2 disease.

Conflict of interests

The authors declare no conflict of interest.

Appendix A
Supplementary data

The following are Supplementary data to this article:

J.R. Lechien, C.M. Chiesa‐Estomba, S. Place, et al.
Clinical and Epidemiological Characteristics of 1,420 European Patients with mild‐to‐moderate Coronavirus Disease 2019.
L.A. Vaira, G. Deiana, A.G. Fois, et al.
Objective evaluation of anosmia and ageusia in COVID-19 patients: Single-center experience on 72 cases.
Head & Neck., (2020), pp. 1-7
J.R. Lechien, M.D. Cabaraux, C.M. Chiesa-Estomba, et al.
Objective olfactory evaluation of self-reported los of smell in a case series of 86 COVID-19 patientes.
N. Bhattacharyya, L.J. Kepnes.
Contemporary assessment of the prevalence of smell and taste problems in adults.
Laryngoscope., 125 (2015), pp. 1102-1106
L. Zou, F. Ruan, M. Huang, et al.
SARS-CoV-2 viral load in upper respiratory specimens of infected patients.
N Engl J Med., 382 (2020), pp. 1177-1179
S.B. Gane, C. Kelly, C. Hopkins.
Isolated sudden onset anosmia in COVID-19 infection. A novel syndrome?.
L.A. Vaira, C. Hopkins, G. Salzano.
Olfactory and gustatory function impairment in COVID-19 patients: Italian objective multicenter-study.

Please cite this article as: Ninchritz-Becerra E, Soriano-Reixach MM, Mayo-Yánez M, Calvo-Henríquez C, Martínez-Ruiz de Apodaca P, Saga-Gutiérrez C, et al. Evaluación subjetiva de las alteraciones del olfato y del gusto en pacientes con afectación leve por COVID-19 en España. Med Clin (Barc). 2021;156:61–64.

Copyright © 2020. Elsevier España, S.L.U.. All rights reserved
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