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.

Omega-3 supplementation in postviral olfactory dysfunction: a pilot study.

BACKGROUND: This study aimed to examine whether omega-3 supplementation would support olfactory recovery among postviral olfactory dysfunction patients. METHODOLOGY: Patients with postviral olfactory dysfunction were included in this non-blinded, prospective pilot study. Structured medical history was taken from the patients, including the following: age, sex, history of COVID-19 infection, and duration of symptoms. Patients were randomly assigned to receive olfactory training only (control group) versus olfactory training with omega-3 supplementation (treatment group). All patients exposed themselves twice a day to four odours (phenyl ethyl alcohol [rose], eucalyptol [eucalyptus], citronellal [lemon], and eugenol [cloves]). Olfactory function was measured before and after training using 'Sniffin' Sticks', comprised of tests for odour threshold, discrimination, and identification. The average interval between olfactory tests was 3 months. RESULTS: Fifty-eight patients were included in the study, 25 men and 33 women. Generally, an improvement in olfactory scores was observed. Compared to the control group, the improvement in odour thresholds was more pronounced in the omega-3 group. Age, sex, and duration of symptoms had no effect on olfactory scores among both control and treatment groups. CONCLUSION: Overall, the present results indicate that omega-3 supplementation may be an option for adjunct therapy with olfactory training in patients with postviral olfactory dysfunction.

Electrophysiological and olfactometric evaluation of long-term COVID-19.

COVID-19 is a public health emergency with cases increasing globally. Its clinical manifestations range from asymptomatic and acute respiratory disease to multiple organ dysfunction syndromes and effects of COVID-19 in the long term. Interestingly, regardless of variant, all COVID-19 share impairment of the sense of smell and taste. We would like to report, as far as we know, the first comprehensive neurophysiological evaluation of the long-term effects of SARS-CoV-2 on the olfactory system with potential-related neurological damage. The case report concerns a military doctor, with a monitored health history, infected in April 2020 by the first wave of the epidemic expansion while on military duty in Codogno (Milan). In this subject, we find the electrophysiological signal in the periphery, while its correlate is absent in the olfactory bulb region than in whole brain recordings. In agreement with this result is the lack of metabolic signs of brain activation under olfactory stimulation. Consequently, quantitative and qualitative diagnoses of anosmia were made by means of olfactometric tests. We strongly suggest a comprehensive series of olfactometric tests from the first sign of COVID-19 and subsequent patient assessments. In conclusion, electrophysiological and metabolic tests of olfactory function have made it possible to study the long-term effects and the establishment of neurological consequences.

Patients with COVID-19-associated olfactory impairment also show impaired trigeminal function.

OBJECTIVE: Next to olfactory function, the nose can also perceive chemestetic sensations mediated by the trigeminal nerve. While olfactory dysfunction as a symptom of COVID-19 is well described, there has been little research on the limitation of other nasal sensory inputs due to SARS-CoV-2 infection. The aim of this study was to determine possible limitations of nasal chemesthesis after COVID-19 infection by a psychophysiological diagnostic tool. METHODS: In 65 patients with a PCR-confirmed, former COVID-19 disease, olfaction was tested by means of a sniffin' sticks test, tasting by taste sprays and chemesthesis with a menthol dilution series. The subjective self-assessment of the patients was recorded via a questionnaire. RESULTS: We found a restriction of nasal chemesthesis and the extent correlated with the loss of smell, as well as with the values of the taste score, but not with subjective self-assessment. CONCLUSION: Not only the ability to smell and taste, but also nasal chemesthesis is affected by COVID-19.

Sniffin' Sticks Screening 12 test: Presentation of odours on filter paper improves the recognition rate.

To the Editor: Monitoring of olfactory function and diagnosis of olfactory disorders using the pen-based "Sniffin' Sticks test" is problematic during the SARS-CoV-2 pandemic due to hygienic concerns. The aim of this study was to find out whether the results of olfactory testing obtained by presenting odours on a single-use filter paper is identical to performing the test by presenting the odour pens according to the manufacturer's manual.

Persisting olfactory dysfunction improves in patients 6 months after COVID-19 disease.

BACKGROUND: Smell disorders persist in about half of the patients with other symptoms of COVID-19 disease, but the exact duration of the symptoms is yet unknown. Especially, only a few studies used validated olfactory tests for this. AIMS/OBJECTIVES: The aim of this study was to investigate how many patients with olfactory function impairment, which was detected in a validated olfactory test 3 months after COVID-19 disease, showed improvement in olfactory function after 6 months. METHODS: About 26 patients with a PCR-confirmed, former COVID-19 disease, with an impaired olfactory function after three months, were included in the study. The olfactory function was evaluated with the sniffing sticks test, the taste function with taste sprays. RESULTS: Smelling function improved in all but one patient (96%). All measured subitems, i.e. olfactory threshold, identification and discrimination of odours significantly improved. In the whole mouth taste test all patients showed normal taste function. CONCLUSIONS AND SIGNIFICANCE: 6 months after COVID-19 disease, olfactory function improves in just about all patients. Long-term measurements must investigate whether complete regeneration of the olfactory function will occur in all patients.

Widespread sensory neuropathy in diabetic patients hospitalized with severe COVID-19 infection.

AIMS: To characterize the distribution and severity of sensory neuropathy using a portable quantitative sensory testing (QST) device in diabetic patients (DM) hospitalized with severe COVID-19 infection. METHODS: Four patients with diabetes and severe SARS-CoV-2 requiring non-invasive ventilation for a protracted duration underwent clinical, laboratory and radiologic assessment and detailed evaluation of neuropathic symptoms, neurological assessment, QST on the dorsum of the foot and face using NerveCheck Master with assessment of taste and smell. RESULTS: All four subjects developed neuropathic symptoms characterized by numbness in the feet with preserved reflexes. QST confirmed symmetrical abnormality of vibration and thermal thresholds in both lower limbs in all patients and an abnormal heat pain threshold on the face of two patients and altered taste and smell. CONCLUSIONS: Severe COVID-19 infection with hypoxemia is associated with neuropathic symptoms and widespread sensory dysfunction in patients with DM.

Evaluation of Olfactory Function With Objective Tests in COVID-19-Positive Patients: A Cross-Sectional Study.

OBJECTIVE: Olfactory dysfunction is relatively high in coronavirus disease 2019 (COVID-19) patients. The aim of this study is to investigate the incidence of olfactory disorder objectively in patients with laboratory-confirmed COVID-19 infection. MATERIAL AND METHOD: The study included 31 healthy controls and 59 COVID-19 patients who were diagnosed and treated in the COVID departments in a tertiary hospital. The patients with corona virus infection were screened by a questionnaire and were classified into 2 groups as either group 2 (patients without self-reported smell loss) or group 3 (patients with self-reported smell loss). Age and gender matched healthy controls who do not have chronic nasal condition or nasal surgery history comprised the control group (group 1). All of the patients and subjects in the control group were tested by the Sniffin' Sticks test. All of the answers and scores were recorded, and the comparisons were made. RESULTS: The rate of self-reported smell and taste loss in all COVID-19 patients in this study was 52.5% and 42%, respectively. There was a significant difference in threshold, discrimination, identification, and Threshold, Discrimination, Identification (TDI) scores between groups 1 and 2. When the comparisons between group 1 and 3 were made, again threshold, discrimination, identification, and TDI scores were significantly different. The comparison between groups 2 and 3 demonstrated a significant difference in discrimination, identification, and TDI scores, but threshold score was not different statistically. With questionnaire, the rate of olfactory dysfunction in COVID-19 patients was 52.5%, but with objective test, the rate was calculated as 83%. CONCLUSION: Olfactory and gustatory dysfunctions are common in COVID-19 patients. According to findings with the objective test method in this study, smell disorder in COVID-19 patients was much higher than those detected by questionnaires.

Gaining Back What Is Lost: Recovering the Sense of Smell in Mild to Moderate Patients After COVID-19.

The purpose of our cohort study was to quantify olfactory deficits in Coronavirus disease 2019 (COVID-19) patients using Sniffin' Sticks and a pre-post design to evaluate olfactory recovery. Thirty adult patients with laboratory-confirmed mild to moderate forms of COVID-19 underwent a quantitative olfactory test performed with the Sniffin' Sticks test (SST; Burghardt, Wedel, Germany), considering olfactory threshold (T), odor discrimination (D), and odor identification (I). Results were presented as a composite TDI score (range 1-48) that used to define functional anosmia (TDI ≤ 16.5), hyposmia (16.5 < TDI < 30.5), or functionally normal ability to smell (TDI ≥ 30.5). Patients also self-evaluated their olfactory function by rating their ability to smell on a visual analogue scale (Visual Analog Scale rating) and answering a validated Italian questionnaire (Hyposmia Rating Scale). Patients were tested during hospitalization and about 2 months after symptoms onset. During the hospitalization, the overall TDI score indicated that our cohort had impairments in their olfactory ability (10% was diagnosed with anosmia and more than 50% were hyposmic). Almost all patients showed a significant improvement at around 1 month following the first test and for all the parts of the SST except for odor identification. None of the subjects at 1 month was still diagnosed with anosmia. We also quantified the improvement in the TDI score based on initial diagnosis. Anosmic subjects showed a greater improvement than hyposmic and normosmic subjects. In conclusion, within a month time window and 2 months after symptoms' onset, in our cohort of patients we observed a substantial improvement in the olfactory abilities.

Olfactory dysfunction in patients after recovering from COVID-19.

BACKGROUND: Smell and taste disorders occur in COVID-19 with a high prevalence, but little is known about the duration of the symptoms. In particular, studies using validated olfactory tests are very rare to date. AIMS/OBJECTIVES: The aim of this study was to determine the olfactory function of COVID-19 recoveries by a detailed olfactory test. METHODS: 91 patients with PCR-confirmed, past COVID-19 disease were included. Olfactory history was taken using a questionnaire. Olfactory function was evaluated with the sniffin' sticks test, tasting function with taste sprays. RESULTS: 80 patients had experienced sudden olfactory loss during the course of disease and at the time of testing, 33 patients subjectively still had an impaired olfactory sense. Around 8 weeks had passed since the onset of symptoms. 45.1% of the tested individuals were still hyposmic according to the olfactory test while 53.8% showed an olfactory performance within the normal range. Patients' self-assessment correlated poorly with the measured olfactory performance. CONCLUSIONS AND SIGNIFICANCE: Half of the patients with an olfactory loss as a symptom of COVID-19 still have olfactory impairments after two months, although not all of these patients subjectively notice a restriction. Long-term measurements must confirm whether all affected patients will make full recovery.

Remote psychophysical evaluation of olfactory and gustatory functions in early-stage coronavirus disease 2019 patients: the Bologna experience of 300 cases.

BACKGROUND: An objective evaluation of coronavirus disease 2019 in the first days of infection is almost impossible, as affected individuals are generally in home quarantine, and there is limited accessibility for the operator who should perform the test. To overcome this limitation, a recently validated psychophysical self-administered test was used, which can be performed remotely in the assessment of early-stage coronavirus disease 2019 patients. METHODS: Olfactory and gustatory functions were objectively assessed in 300 patients in the first 7 days from coronavirus disease 2019 symptom onset. RESULTS: Seventy per cent of the patients presented olfactory and/or gustatory disorders. The dysfunctions detected were mainly complete anosmia (47 per cent) or ageusia (38 per cent). A significant correlation was found between taste dysfunction and female gender (odds ratio = 1.936, p = 0.014) and fever (odds ratio = 2.132, p = 0.003). CONCLUSION: The psychophysical evaluation protocol proposed is an effective tool for the fast and objective evaluation of patients in the early stages of coronavirus disease 2019. Chemosensitive disorders have been confirmed to be frequent and early symptoms of the coronavirus infection, and, in a significant number of cases, they are the first or only manifestation of coronavirus disease 2019.

Validation of a self-administered olfactory and gustatory test for the remotely evaluation of COVID-19 patients in home quarantine.

BACKGROUND: Chemosensitive disorders are very frequent in the early stages of COVID-19 and in paucisymptomatic cases. These patients are typically placed in home quarantine. This study has the aim of validating a new olfactory and gustatory objective evaluation test in these patients. METHODS: Thirty-three home-quarantined COVID-19 patients have undergone a self-administered chemosensitive test the day before the control swab. On this occasion, the patients underwent operator-administered already validated tests. The results were finally compared. RESULTS: The differences between the results of the two tests were not significant for both the olfaction (P =.201) and the taste (P =.180). CONCLUSION: The olfactory and gustatory evaluation by self-administered test can be considered a valid tool, fundamental for obtaining objective qualitative and quantitative data on the extent of chemosensitive disorders in home-quarantined COVID-19 patients.