Long-lasting olfactory dysfunction in COVID-19 patients.

OBJECTIVES: Olfactory dysfunction (OD) is a common symptom of Coronavirus Disease 2019 (COVID-19). Although many patients have been reported to regain olfactory function within the first month, long-term observation reports vary. Therefore, we aimed to assess the course of chemosensory function in patients diagnosed with COVID-19 within 3-15 months after the infection. METHODS: One hundred and two patients (71 females and 31 males; mean age 38.8 years) diagnosed with laboratory-confirmed COVID-19 and subjective OD participated in this single-center study 111-457 days after onset of OD. Patients first performed chemosensory tests at home, followed by psychophysical testing (Sniffin' Sticks (TDI), 27-item Candy Smell Test (CST), Taste Strips Test (TST)) in the clinic. Questionnaires regarding importance of olfaction (IOQ) and olfactory-specific quality of life (QOD) were applied at both timepoints. RESULTS: After a mean 216 days (SD 73; range 111-457) between OD onset and follow-up testing, the mean Sniffin' Sticks (TDI) score was 27.1 points (SD 5.8; range 4.25-38.5): 4.0% were anosmic, 72.5% hyposmic, and 23.5% normosmic. At follow-up testing, 73.5% of patients reported improvement, 5.9% deterioration, and 20.6% no change in OD. Moreover, full recovery of self-perceived smell, flavor, and taste was not observed. According to questionnaires, the individual importance of smell did not change, but participants showed improvement in OD-related quality of life (p < 0.001) and had increased parosmia scores (p = 0.014) at follow-up. CONCLUSION: Our results show that long-lasting OD after SARS-CoV-2 infection is a common symptom. The majority of patients had OD in the range of hyposmia, which was confirmed by comprehensive smell tests.

Pediatric olfactory home testing using regular household items: A cross-over validation study.

OBJECTIVE: To develop an olfactory test that can be conducted by an untrained person using common household items and to introduce a German version of the Chemosensory Pleasure Scale for Children (CPS-C(de)). METHODOLOGY: This olfactory home test was developed in phases including evaluation of odors for suitability in a home setting. Parents of 50 children (ages 6-17) were then equipped with instruction manuals and participants were tested twice in a cross-over design. A validated pediatric olfactory test (the Universal Sniff test (U-Sniff)) served as the comparative gold standard. Additionally, a Chinese-English-German "back-and-forth" translation was conducted to establish the CPS-C(de) and was tested for empirical validity. RESULTS: Fourteen items were tested for feasibility, and all were identified on a sufficient rate (≥66%, mean ±â€¯SD of 93.3% ±â€¯9.5%). Bland Altman Plot analysis between home testing and the U-Sniff test was nearly identical (bias = 0.04). CPS-C(de) showed similar results to the original Chinese version and a moderate correlation was found between CPS-C(de) scores and Body Mass Index of children (r30 = -0.527, p = 0.003). CONCLUSIONS: Remote olfactory testing in children using household items is feasible. The CPS-C(de) may be of value for future olfactory studies.

Depression Symptoms and Olfactory-related Quality of Life.

OBJECTIVES: Patients with olfactory dysfunction (OD) frequently report symptoms of depression. The objective of this study was to determine how clinical characteristics and olfactory-related quality of life (QoL) measures associate with the likelihood for major depressive disorders (MDDs). METHODS: A total of 192 OD patients were included. Olfactory function was measured using all three subtests of the Sniffn' Sticks test. Olfactory-related quality of life (QoL) was evaluated using the Questionnaires of Olfactory Dysfunction (QOD)-negative (NS) and -positive statement (PS). The likelihood for MDD was assessed using the Patients Health Questionnaire-2 (PHQ-2). Demographics and disease-specific variables (etiology and duration of OD) were collected. Univariate and multivariable analyses were used to associate disease-specific variables and the QOD with the outcome of the PHQ-2. Additionally, the predictive ability of the QOD-NS to predict depressive symptoms was calculated. RESULTS: In univariate analysis, COVID-19 related smell loss, the QOD-NS, and the QOD-PS were significantly associated with the PHQ-2. In multivariable analyses adjusting for QoL measures, the QOD-NS (ß = 0.532, p < 0.001) and sinonasal OD (compared with postinfectious OD) were significantly associated with the PHQ-2 (ß = 0.146, p = 0.047). When omitting QoL measures from multivariable analyses, only COVID-19 related OD (compared with postinfectious OD) was significantly associated with the PHQ-2 (ß = 0.287, p = 0.009). A QOD-NS score > 20.5 had 70.13% sensitivity and 76.32% specificity for detecting symptoms of depression. CONCLUSION: Our results suggest that COVID-19 related OD might be associated with a higher likelihood for MDD. Furthermore, we showed that the QOD-NS score might be helpful to predict symptoms of depression in OD patients. LEVEL OF EVIDENCE: 4 Laryngoscope, 132:1829-1834, 2022.

Olfactory-related Quality of Life Adjustments in Smell Loss during the Coronavirus-19 Pandemic.

BACKGROUND: Previous studies provided the first evidence that the importance of olfaction decreases with the duration of olfactory dysfunction (OD). OBJECTIVE: To evaluate differences in olfactory-related quality of life (QoL) between patients with new-onset and persistent smell loss (>4 weeks) during the coronavirus-19 (COVID-19) pandemic and patients with persistent postinfectious OD (PIOD) that were recruited before the pandemic. METHODS: This was a retrospective study that included 149 patients with self-reported OD. The olfactory-related QoL was measured using the questionnaire of OD (QOD). The QOD measures the degree to which patients (i) adjust and cope with smell loss (QOD-positive statement [QOD-PS]), (ii) suffer from distorted odor perceptions (QOD-parosmia [QOD-PAR]), and (iii) suffer from smell loss in general (QOD-negative statement [QOD-NS]). Self-perceived chemosensory function, demographics, olfactory function, and duration of smell loss were evaluated. Analyses of variance were used to depict differences in QoL-outcomes between different OD groups. RESULTS: All patients included during the COVID-19 pandemic reported an extensive loss of chemosensory functions of smell, taste, and flavor perception. Psychophysical retronasal screening testing showed olfactory impairments in more than half of these patients. One-way analysis of variance and posthoc tests revealed that the QOD-NS was significantly higher in the new-onset OD group than the PIOD group. At the same time, the QOD-PS score was significantly higher in the PIOD and the persistent COVID-19 OD group than in the new-onset OD group. CONCLUSION: We showed that patients with persistent OD experienced better olfactory-related adjustment and lower QoL-impairment scores than those with recent-onset smell loss, suggesting that the olfactory-related QoL might change as a function of time after symptom onset.

Retronasal olfactory testing in early diagnosed and suspected COVID-19 patients: a 7-week follow-up study.

OBJECTIVES: Olfactory dysfunction (OD) constitutes a major symptom in Coronavirus Disease 2019 (COVID-19). Yet, most data on smell loss rely on the evaluation of orthonasal olfactory performance. Therefore, we aimed to assess retronasal olfactory function (ROF) over a period of several weeks in proven and suspected COVID-19 patients. METHODS: One hundred and one subjects with suspected or laboratory-proven COVID-19 participated in this study. In patients with OD no longer than 4 weeks after initial symptom onset, ROF was measured with the 7-item Candy Smell Test ten times over 7 weeks. RESULTS: Olfactory function was decreased in the investigated patients and remained decreased over the course of 7 weeks. One-way repeated-measures ANOVA revealed no significant difference of ROF between different measurement time points. However, self-assessment of smell and flavour improved significantly (p = 0.013 and p = 0.043), but did not show complete recovery. CONCLUSION: The current investigation revealed significant improvements in subjective smell and flavour perception over the course of 7 weeks in proven and suspected COVID-19 patients suffering from acute OD. However, objectively measured ROF based on a screening test revealed no improvements within the same time period.

Decrease and Recovery of Olfactory and Gustatory Function in a Case of SARS-CoV-2 Infection.

Self-reported chemosensory dysfunction in severe acute respiratory syndrome coronavirus 2 patients is common. We present a case of reversible smell loss in a young patient with mild coronavirus disease 2019 infection assessed with established testing methods over a period of 8 weeks.