Table 1.
Gustatory dysfunction associated with coronavirus disease 2019 (COVID-19).
| Subjects | Severity of Disease | Country or Ethnicity | Number of Patients | Mean or Median Age (Range) | Male (%) | Assessment Method | Symptom | Prevalence (%) | Reference |
|---|---|---|---|---|---|---|---|---|---|
| HP diagnosed according to the official guideline and by SARS-CoV-2 nucleic acid detection | Mild to critical | China | 108 | 52.0 (one patient excluded) |
48.1 | Self-reported questionnaire | Amblygeusia | Total: 47.2 Male: 36.5 Female: 57.1 |
Chen et al. [9] * |
| HP diagnosed by RT-PCR test | Mild to moderate | 12 European hospitals (European 93.3%, African 3.6%, South American 2.7%, North American 0.2%, Asian 0.2%) | 417 | 36.9 (19–77) |
36.9 | Self-reported questionnaire about salty, sweet, bitter and sour taste modalities | Gustatory dysfunction characterized by impairments of four tastes | 88.8 | Lechien et al. [22] * |
| HP diagnosed by real-time RT-PCR test | Mild to severe | Iran | 60 | 46.6 | 66.7 | Validated UPSIT | Taste loss Taste and smell loss |
6.7 16.7 |
Moein et al. [24] |
| HP (diagnostic method, NS) |
NS | Italy | 59 | 60 (50–74) |
67.8 | Self-reported questionnaire | Gustatory dysfunction Dysgeusia Ageusia |
28.8 8.5 1.7 |
Giacomelli et al. [27] * |
| Patients diagnosed by RT-PCR test | Mild (93.1%) Moderate to severe (6.9%) |
USA | 59 | (18–79) | 49.2 | Self-reported online questionnaire | Ageusia | 71.2 | Yan et al. [28] |
| Patients diagnosed by RT-PCR test | Mild to moderate | Subscribers of COVID-19 symptom tracker application of UK | 579 | 40.8 | 30.9 | Self-reported questionnaire | Ageusia and anosmia | 59.4 | Menni et al. [29] # |
| HP diagnosed by real-time RT-PCR test | Non-severe (58.9%) Severe (41.1%) |
China | 214 | 52.7 | 40.7 | Retrospective symptom survey | Taste impairment | 5.6 | Mao et al. [30] * |
| Patients diagnosed presumably by RT-PCR test | Mild to moderate | Italy | 72 | 49.2 (26–90) |
37.5 | Objective evaluation using four tastants | Mild hypogeusia Moderate hypogeusia Severe hypogeusia Ageusia |
22.2 15.3 9.7 1.4 |
Vaira et al. [31] * |
| HQP diagnosed by RT-PCR test | Mild | Italy | 202 | 56 (45–67) |
48.0 | Self-reported questionnaire | Taste/smell alteration Very mild Mild or light Moderate Severe |
64.4 2.5 11.4 13.4 13.4 |
Spinato et al. [32] * |
| HP diagnosed by RT-PCR test | Mild | Israel | 42 | 34 (15–82) |
54.8 | Self-reported questionnaire | Dysgeusia | 33.3 | Levinson et al. [33] * |
| Patients diagnosed by real-time RT-PCR test | NS | Italy | 72 | 49.7 (19–70) |
54.2 | Self-report of symptoms | Gustatory dysfunction Dysgeusia |
72.2 25.0 |
Gelardi et al. [34] |
| OP diagnosed by RT-PCR test or clinical features | NS | France | 1487 | 44 (32–57) |
47.1 (35 excluded) |
Observational survey | Gustatory dysfunction Ageusia |
50.9 28.4 |
Lapostolle et al. [35] |
| Patients diagnosed by RT-PCR test | NS | France | 68 | NS | NS | Self-reported questionnaire | Hypogeusia | 61.8 | Bénézit et al. [36] |
| IP (37%) and OP (63%) diagnosed by real-time RT-PCR | Mild to severe | France | 54 | 47 | 33.3 | Self-reported symptoms | Dysgeusia | 85.2 | Klopfenst et al. [37] |
| HP diagnosed by RT-PCR test | Non-severe to severe | Spain | 79 | 61.6 | 60.8 | Self-reported questionnaire | Ageusia Hypogeusia Dysgeusia |
17.7 8.9 10.1 |
Beltrán- Corbellini et al. [38] |
| HP diagnosed by real-time RT-PCR test | Severe and others | USA | 16 | 65.5 | 75.0 | Self-reported questionnaire | Dysgeusia | 18.8 | Aggarwal et al. [39] |
| HP diagnosed by real-time RT-PCR test | Mild to severe | Singapore | 154 | NS | NS | Self-reported questionnaire | Gustatory or olfactory dysfunction | 22.7 | Wee et al. [40] |
| OP and IP diagnosed by RT-PCR test | Mild (79.7%) Severe (20.3%) |
USA (White 30.8%, Black 11.5%, Hispanic 26.9%, Asian 15.4%, Others 15.4%) |
OP: 102 IP: 26 |
OP: 43 (34–54) IP: 53.5 (40–65) |
OP: 51 IP: 34.6 |
Self-reported taste and smell sense | Dysgeusia | OP: 62.7 IP: 23.1 |
Yan, et al. [41] |
| HQP diagnosed presumably by RT-PCR test | Asymptomatic (27.3%) Mild (45.4%) Moderate (27.3%) |
Italy | 33 | 47.2 (26–64) |
33.3 | Self- or operator- administered test using four tastants | Mild hypogeusia Moderate hypogeusia Severe hypogeusia Ageusia |
24.2 12.1 9.1 6.1 |
Vaira et al. [42] * |
| Patients diagnosed by real-time RT-PCR test | Mild | South Korea | 172 | 26 (22–47) |
38.4 | Self-reported questionnaire | Hypogeusia | 33.7 | Kim et al. [43] |
| OP diagnosed by RT-PCR test | NS | Germany | 72 | 38 (21–87) |
56.9 | Self-reported questionnaire | Gustatory dysfunction | 69.4 | Luers et al. [44] |
| Patients (diagnostic method, NS) | All stages Asymptomatic to mild (73.4%) Moderate (10.6%) Severe (2.2%) Critical (1.3%) |
South Korea | 3191 2342 339 71 41 |
44 (25–58) |
36.4 | Telephone interview | Ageusia | 11.1 | Lee et al. [45] * |
| Patients diagnosed by RT-PCR test | NS | Switzerland | 103 | 46.8 | 48.5 | Self-reported questionnaire | Gustatory dysfunction | 65.0 | Speth et al. [46] * |
| Patients diagnosed by RT-PCR test | Mild to moderate | 18 European hospitals (European 91.4%, African 4.6%, American 2.7%, Asian 0.8%) | 1420 | 39.2 | 32.3 | Self-reported questionnaire | Gustatory dysfunction | 54.2 | Lechien et al. [47] |
| OP and IP (diagnostic method, NS) | NS | USA | 145 | 40 | 35.2 | Self-reported questionnaire | Taste or smell change | 65.5 | Roland et al. [48] |
| HP (53.3%) and HQP (46.7%) diagnosed presumably by RT-PCR test | Asymptomatic (2.9%) Mild (48.7%) Moderate (40.6%) Severe (7.8%) |
Italy | 345 | 48.5 (23–88) |
42.3 | Objective evaluation using four tastants | Mild hypogeusia Moderate hypogeusia Severe hypogeusia Ageusia |
22.6 7.2 4.6 10.4 |
Vaira et al. [49] * |
| Patients diagnosed by RT-PCR test | Mild to moderate | Belgium (Caucasian 92.9%, North African 7.1%) |
28 | 44.0 | 32.1 | Self-reported questionnaire based on taste and smell components of NHANES | Dysgeusia (salty, sweet, bitter, and sour tastes) | 60.7 | Lechien et al. [50] # |
| HP diagnosed by RT-PCR test | NS | Germany | 47 | 63.8 | 27.7 | Self-reported questionnaire | Hypogeusia | 19.1 | Bertlich et al. [51] |
| OP diagnosed by real-time RT-PCR test | NS | France | 95 | 39.8 (18–73) |
16.8 | Self-reported questionnaire | Dysgeusia | 65.3 | Zayet et al. [52] |
| OP (diagnostic method, NS) | Mild to moderate | Italy | 95 | NS | NS | Self-reported questionnaire | Gustatory dysfunction | 50.5 | De Maria et al. [53] |
| Patients diagnosed by RT-PCR test | NS | UK USA |
Total: 7178 UK: 6452 USA: 726 |
UK: 41.3 USA: 44.7 |
UK: 28.1 USA: 21.9 |
Self-reported questionnaire via COVID-19 symptom tracker application | Taste and smell loss | Total: 65.0 UK: 64.8 USA: 67.5 |
Menni et al. [54] |
| Patients diagnosed by RT-PCR test | NS | Italy | 355 | 50 | 54.1 | Self-reported questionnaire | Gustatory dysfunction | 65.4 | Dell’Era et al. [55] |
| HP (diagnostic method, NS) | NS | Italy | 103 | 55 | 57.3 | Self-reported questionnaire | Dysgeusia | 46.6 | Liguori et al. [56] |
| Patients diagnosed by real-time RT-PCR test | NS | Turkey | 64 | 37.8 (21–77) |
39.1 | Self-reported questionnaire | Dysgeusia Hypogeusia Ageusia |
25.0 56.3 12.5 |
Sayin et al. [57] |
| IP and HQP diagnosed by real-time RT-PCR test | Mild to severe | Italy | IP: 295 HQP: 213 |
IP: 61.9 (24–91) HQP: 44.7 (18–74) |
IP: 69.2 HQP: 38.0 |
Self-reported questionnaire | Gustatory dysfunction | IP: 51.9 HQP: 78.9 |
Paderno et al. [58] |
| Patients diagnosed by RT-PCR test | Mild to critical | Total Chinese 60.7% French 29.4% German 9.9% |
394 239 116 39 |
38.8 30.5 48.1 43.1 |
57.1 58.4 59.6 48.1 |
Self-reported questionnaire | Gustatory dysfunction in Chinese French German |
12.6 43.1 51.3 |
Qiu et al. [59] * |
| Household contacts of mildly symptomatic HQP (diagnostic test, NS) | NS | Italy | 54 | NS | NS | Self-reported questionnaire | Taste or smell loss | 63.0 | Boscolo-Rizzo et al. [60] |
| Patients diagnosed by real-time RT-PCR test | NS | USA | 42 | NS | NS | Self-reported questionnaire | Taste loss | 57.1 | Dawson et al. [61] |
| Patients diagnosed by RT-PCR test | NS | France | 198 | NS | NS | Self-reported questionnaire | Taste disorder | 46.5 | Tudrej et al. [62] |
| Patients positive for SARS-CoV-2 or quarantined patients (diagnostic test, NS) | NS | Spain | 909 | 34 (16–74) |
31.3 | Self-reported online questionnaire | Gustatory dysfunction Ageusia Hypogeusia Dysgeusia |
93.0 64.1 28.2 2.4 |
Gómez- Iglesias et al. [63] |
| Patients diagnosed by LT or CA (diagnostic tests, NS) | NS | Europe, North, Central and South America, Oceania, Middle East, Africa, Southeast Asia | Total: 4039 LT: 1402 CA: 2637 |
LT: 40.7 CA: 41.7 |
LT: 23.9 CA: 29.7 |
Self-reported questionnaire of changes in specific taste qualities | Single taste impairment Two or more taste qualities impairment |
11 48 |
Parma et al. [64] |
| NHP (quarantined in hotel) diagnosed by RT-PCR test | Mild | Israel | 128 | 36.3 (18–73) |
45.3 | Self-reported questionnaire | Gustatory dysfunction | 52.3 | Biadsee et al. [65] * |
| Patients (admitted to hospital or managed in community) diagnosed by real-time RT-PCR test | NS | UK | 141 | 45.6 (20–93) |
58.9 | Self-reported questionnaire | Ageusia | 63.1 | Patel et al. [66] |
| OP (92.0%) and IP (8.0%) diagnosed by RT-PCR test | Mild to moderate | 18 European hospitals (White 88.5%, South American 6.6%, North African 2.3%, Others 2.6%) |
2013 | 39.5 | 34.0 | Self-reported questionnaire based on taste and smell components of NHANES | Gustatory dysfunction | 56.4 | Lechien et al. [67] |
| Patients diagnosed by RT-PCR test | NS | Canada | 134 | 57.1 | 47.8 | Self-reported questionnaire | Dysgeusia | 63.4 | Carignan et al. [68] |
| IP (47.1%) and OP (52.9%) diagnosed by real-time RT-PCR test | Mild to critical | France | 70 | 56.7 (19–96) |
41.4 | Self-reported questionnaire | Dysgeusia | 48.6 | Zayet et al. [69] |
| Patients diagnosed by RT-PCR test | NS | Spain | 131 | 50.4 | 42.6 | Self-reported questionnaire | Gustatory dysfunction Ageusia |
56.5 42.7 |
Abalo-Lojo et al. [70] * |
| HP diagnosed by RT-PCR | NS | Italy (Caucasian) | 100 | 65 (29–94) |
60.0 | Self-reported questionnaire | Gustatory dysfunction | 69.0 | Meini et al. [71] |
| HP diagnosed by real-time RT-PCR | Mild to critical | USA | 50 | 59.6 | 58.0 | Reviewed neurologic symptoms | Dysgeusia and hypogeusia | 10.0 | Pinna et al. [72] |
| NHP diagnosed by RT-PCR test | Mild to moderate | Poland | 1942 | 50 | 39.8 | Self-reported questionnaire | Gustatory dysfunction | 47.5 | Sierpiński et al. [73] |
| Patients diagnosed by RT-PCR test | Asymptomatic or oligosymptomatic | Poland | 52 | 21.7 (19–26) |
98.1 | Self-reported questionnaire using four tastants | Taste or smell disturbance Sweet taste disorder |
65.0 71.2 |
Adamczyk et al. [74] *,# |
| Patients diagnosed by RT-PCR test | NS | Latin Americans (Argentina 21.4%, Peru 17.2%, Colombia 15.5%, Uruguay 13.1%) | 542 | 34 (18–88) |
40.2 | Self-reported online questionnaire | Gustatory dysfunction (salty, sweet, sour, and bitter tastes) | 61.4 | Chiesa- Estomba et al. [75] |
| OP diagnosed by RT-PCR test | NS | Canada | 56 | 38.0 | 41.1 | Self-reported symptoms | Dysgeusia/ageusia | 57.1 | Lee et al. [76] |
| Patients diagnosed by real-time RT-PCR test | NS | Iceland | 1211 | 41.3–44.4 | 49.4–52.0 | Self-reported symptoms | Taste or smell loss | 9.7 | Gudbjartsson et al. [77] |
| Discharged patients diagnosed by real-time RT-PCR test | Severe Non-severe |
China | 1172 | 61 | 49.2 | Self-reported questionnaire | Ageusia | 20.6 | Song et al. [78] |
| HP (23.5%) and NHP (76.5%) diagnosed by RT-PCR test | NS | France | 115 | 47 (20–83) |
29.6 | Self-reported questionnaire | Gustatory dysfunction | 55.7 | Chary et al. [79] * |
| Patients diagnosed by RT-PCR test | NS | European 88% Asian 12% |
50 | 37.7 (18–65) |
60 | Self-reported questionnaire | Gustatory dysfunction | 70.0 | Freni et al. [80] * |
| OP with confirmed and suspected COVID-19 (diagnostic test, NS) | NS | Denmark | 109 | 39.4 | NS | Self-reported online questionnaire | Taste/smell loss Ageusia Hypogeusia |
87.2 69.2 23.1 |
Fjaeldstad et al. [81] |
| HP diagnosed by real-time RT-PCR | NS | Turkey | 81 | 54.2 (18–95) |
50.6 | Gustatory test using four tastants | Gustatory dysfunction | 27.2 | Altin et al. [82] * |
| IP (76.7%) and OP (23.3%) diagnosed by RT-PCR test | NS | Spain | 846 | 56.8 (19–92) |
52.7 | Self-reported questionnaire | Taste loss in IP OP |
48.4 65.0 |
Izquierdo- Dominguez et al. [83] * |
| OP diagnosed by RT-PCR test | Mild to moderate | Turkey | 172 | 37.8 (18–65) |
48.8 | Self-reported questionnaire | Ageusia | 47.1 | Sakalli et al. [84] |
| HP or discharged patients diagnosed by real-time RT-PCR test | NS | Italy | 204 | 52.6 | 53.9 | Retrospective questionnaire | Taste loss | 55.4 | Mercante et al. [85] * |
| HP (diagnostic test, NS) | NS | Italy | 108 | 59 (18–83) |
57 | Self-reported questionnaire | Gustatory dysfunction | 61.1 | Vacchiano et al. [86] |
| OP diagnosed by RT-PCR test | NS | Israel | 73 | (5–50) | NS | Self-reported questionnaire | Taste or smell impairment | 50.7 | Somekh et al. [87] |
| Healthcare personnel diagnosed real-time RT-PCR test | Mild | USA | 51 | NS | 19 | Self-reported questionnaire | Ageusia | 52.9 | Kempker et al. [88] |
| Healthcare workers seropositive for IgG antibodies against SARS-CoV-2 | Mild to severe | Sweden | 410 | 43 | 17.1 | Self-reported questionnaire | Ageusia Anosmia |
49.8 52.9 |
Rudberg et al. [89] |
| Healthcare stuff patients positive for COVID-19 (diagnostic test, NS) | NS | Italy | 300 | 43.6 (33–53) |
25.0 | Self-scoring taste quality using four tastants | Ageusia Severe hypogeusia Moderate hypogeusia Mild hypogeusia |
38.0 7.3 10.1 6.0 |
Petrocelli et al. [90] * |
| HP diagnosed by real-time RT-PCR test | Mild (98.8%) | China | 86 | 25.5 (6–57) |
51.2 | Self-reported questionnaire | Hypogeusia | 38.4 | Liang et al. [91] |
| HP and HQP diagnosed by RT-PCR test | NS | Germany | 41 | 37 | 32 | Self-reported online questionnaire | Gustatory dysfunction | 43.9 | Hintschich et al. [92] |
| Patients tested by real-time RT-PCR test (92.7% with positivity) | NS | France | 55 | 34 (28–43) |
43.6 | Self-reported chemosensory loss | Ageusia Dysgeusia |
36.4 47.3 |
Salmon Ceron et al. [93] * |
| IP (41.0%) and OP diagnosed by RT-PCR test | Mild (59.0%) Moderate to severe (36.7%) Critical (4.3%) |
France | 139 | 48.5 | 37.4 | Retrospective questionnaire one month after recovery | Ageusia | 58.3 | Poncet- Megemont et al. [94] * |
| Health care workers (nurse: 70.7%) diagnosed by RT-PCR test | NS | Italy | 82 | (<35–>55) | 31.7 | Self-reported questionnaire | Dysgeusia | 37.8 | Magnavita et al. [95] |
| OP (96.3%) and IP (3.7%) diagnosed by RT-PCR test or IgG/IgM antibodies test | Mild | European 79.6% Latin American 19.4% |
1043 | 40 (18–78) |
32.8 | Self-reported questionnaire | Gustatory dysfunction | 68.8 | Chiesa- Estomba et al. [96] |
| Healthcare worker patients diagnosed by RT-PCR test | Mild to severe | Spain | 230 | 43 (18–62) |
14.8 | Self-reported questionnaire | Taste alteration | 70.0 | Villarreal et al. [97] * |
| Patients diagnosed by real-time RT-PCR test | NS | Spain | 215 | NS | 20.5 | Self-reported questionnaire | Hypogeusia | 53.0 | Martin-Sanz et al. [98] |
| IP (23.2%) and OP (76.8%) diagnosed by RT-PCR test | NS | Italy | 138 | 51.2 | 49.3 | Self-administered test using four tastants | Gustatory dysfunction | 65.9 | Vaira et al. [99] |
| Patients diagnosed by real-time RT-PCR test | NS | Somalia | 60 | 45.7 | 70.0 | Retrospective symptom survey | Ageusia | 28.3 | Farah Yusuf Mohamud et al. [100] |
| OP diagnosed by RT-PCR test | NS | Spain | 197 | 46.5 (21–89) |
36.5 | Self-reported questionnaire | Ageusia | 65.0 | Rojas-Lechuga et al. [101] |
| HP and NHP diagnosed by real-time RT-PCR test | Mild to critical | France | 70 | 57 | 41.4 | Retrospective symptom survey | Dysgeusia | 48.6 | Klopfenstein et al. [102] |
| IP (28.3%) and OP (71.7%) diagnosed presumably by RT-PCR test | NS | Italy | 106 | 49.6 | 50.0 | Self-administered gustatory test | Ageusia Hypogeusia |
28.3 43.4 |
Vaira et al. [103] |
| HP (72.6%) and NHP (27.4%) diagnosed by RT-PCR test | Mild (18.4%) Moderate (61.4%) Severe (14.3%) Critical (5.8%) |
Turkey | 223 | 51 | 50.7 | Self-reported questionnaire to score symptom severity | Taste loss | 34.5 | Salepci et al. [104] * |
| IP (16.8%) and OP (83.2%) diagnosed by RT-PCR test | Mild to critical | Brazil | 655 | 37.7 | 35.3 | Self-reported questionnaire | Gustatory dysfunction | 76.2 | Brandão Neto et al. [105] |
| Patients diagnosed by real-time RT-PCR test | Asymptomatic and mild to critical |
Qatar | 141 | 35.9 (3–56) |
50.4 | Retrospective symptom survey | Gustatory dysfunction Ageusia |
19.9 11.4 |
Al-Ani et al. [106] * |
| Patients diagnosed by RT-PCR test | NS | Hong Kong | 83 | 36.4 (18–71) |
57.8 | Self-reported questionnaire | Gustatory dysfunction | 43.4 | Cho et al. [107] * |
| HP diagnosed by RT-PCR test | Mild to moderate | Turkey | 143 | 55.6 | 53.8 | Self-reported questionnaire | Gustatory dysfunction | 35.7 | Çalıca Utku et al. [108] * |
| HP diagnosed by RT-PCR test | Manchester triage Green (53.5%) Yellow (30.2%) |
Germany | 43 | 71 (23–94) |
65.1 | Retrospective symptom survey | Dysgeusia | 14.0 | Fistera et al. [109] |
| HP diagnosed by real-time RT-PCR test, IgG/IgM antibodies test or both | Non-severe (60.9%) Severe (39.1%) |
Spain | 841 | 66.4 | 56.2 | Retrospective symptom survey | Non-severe dysgeusia Severe dysgeusia |
7.6 4.0 |
Romero- Sánchez et al. [110] |
| Patients diagnosed by RT-PCR test | NS | Japan | 628 | NS | 53.7 | Self-reported symptoms | Taste or smell loss | 1.0 | Komagamine et al. [111] |
| Patients diagnosed by real-time RT-PCR test | NS | Italy | 111 | 57 (48–67) |
52.3 | Self-reported questionnaire | Dysgeusia | 59.5 | Fantozzi et al. [112] * |
| OP (94.6%) and IP (5.4%) diagnosed by RT-PCR test | Mostly mild | Israel | 112 | 35 | 64.3 | Self-reported questionnaire | Taste change as 1st symptom as ≥2nd symptom |
25 54 |
Klein et al. [113] # |
| Patients diagnosed by RT-PCR test | NS | USA (White 40.5%, Non-white 59.5%) |
368 | (<40–60+) | 45.4 | Self-reported questionnaire | Ageusia | 28.5 | Dixon et al. [114] # |
* indicates studies that were used to characterize symptom prevalence in discussion. # indicates preprint studies that precede formal peer review and publication (as of 28 February 2021). HP: hospitalized patients; NS: not specified; HQP: home-quarantined patients; OP: outpatients; IP: inpatients; NHP: non-hospitalized patients; LT: laboratory objective test; CA: clinical observational assessment; UPSIT: University of Pennsylvania Smell Identification Test; NHANES: National Health and Nutrition Examination Survey.