Chemosensory dysfunction in COVID-19 out-patients.

BACKGROUND: Since the outbreak in China due to coronavirus disease 2019 (COVID-19) various studies have been published describing olfactory and gustatory dysfunction (OGD). OBJECTIVE: The aim was to investigate the frequency and severity of OGD in SARS-CoV-2 (+) out-patients compared to controls with common cold/flu like symptoms and two negative RT-PCR. METHODS: A multicenter cross-sectional study on SARS-CoV-2-positive out-patients (n = 197) and controls (n = 107) from five Spanish Hospitals. Severity of OGD was categorized by visual analogue scale (VAS). Frequency and severity of the chemosensory impairment were analyzed. RESULTS: The frequencies of smell (70.1%) and taste loss (65%) were significantly higher among COVID-19 subjects than in the controls (20.6% and 19.6%, respectively). Simultaneous OGD was more frequent in the COVID-19 group (61.9% vs 10.3%) and they scored higher in VAS for severity of OGD than controls. In the COVID-19 group, OGD was predominant in young subjects 46.5 ± 14.5 and females (63.5%). Subjects with severe loss of smell were younger (42.7 years old vs 45.5 years old), and recovered later (median = 7, IQR = 5.5 vs median = 4, IQR = 3) than those with mild loss of smell. Subjects with severe loss of taste, recovered later in days (median = 7, IQR = 6 vs median = 2, IQR = 2), compared to those with mild loss. CONCLUSION: OGD is a prevalent symptom in COVID-19 subjects with significant differences compared to controls. It was predominant in young and females subjects. Stratified analysis by the severity of OGD showed that more than 60% of COVID-19 subjects presented a severe OGD who took a longer time to recover compared to those with mild symptoms.

The Loss of Smell and Taste in the COVID-19 Outbreak: a Tale of Many Countries.

PURPOSE OF REVIEW: Olfactory dysfunction in upper airway viral infections (common cold, acute rhinosinusitis) is common (> 60%). During the COVID-19 outbreak, frequency of sensory disorders (smell and/or taste) in affected patients has shown a high variability from 5 to 98%, depending on the methodology, country, and study. RECENT FINDINGS: A sudden, severe, isolated loss of smell and/or taste, in the absence of other upper airway inflammatory diseases (allergic rhinitis, chronic rhinosinusitis, nasal polyposis), should alert individuals and physicians on being potentially affected by COVID-19. The evaluation of smell/taste disorders with a visual analogue scale or an individual olfactory or gustatory test, at the hospital or by telemedicine, to prevent contamination might facilitate an early detection of infected patients and reduce the transmission of SARS-CoV-2. During the COVID-19 outbreak, patients with sudden loss of smell should initiate social distancing and home isolation measures and be tested for SARS-CoV-2 diagnostic test when available. Olfactory training is recommended when smell does not come back after 1 month but can be started earlier.

Multiple chemical sensitivity worsens quality of life and cognitive and sensorial features of sense of smell.

Multiple chemical sensitivity (MCS) is characterized by a loss of tolerance to a variety of environmental chemicals. Multiple chemical sensitivity is frequently triggered by exposure to chemical agents, especially insecticides. The aim of the study was to measure the sense of smell and quality of life in patients with MCS compared to the control group. We studied the sense of smell, both sensitive and sensorial characteristics, in female patients with MCS (n = 58, mean 50.5 ± 8.5 years) and healthy female volunteers without rhinosinusal pathologies (n = 60, mean age 46 ± 10.2 years). Olfactometry (Barcelona Smell Test 24/BAST-24), sinonasal symptoms (visual analogue scale/VAS 0-100 mm), and quality of life (Quick Environmental Exposure and Sensitivity Inventory/QEESI) were assessed. Multiple chemical sensitivity patients showed a significant impairment in smell identification (19 ± 12 %; p > 0.05) and forced choice (62 ± 18 %; p > 0.05), but not in smell detection (96 ± 4 %) compared to the control group. Multiple chemical sensitivity patients reported more odours as being intense and irritating and less fresh and pleasant when compared with the control group. Patients scored a high level (40-100) on QEESI questionnaire (symptom severity, chemical intolerances, other intolerances, life impact). In MCS patients, total symptom intensity (VAS/0-700 mm) score was 202 ± 135, while disease severity score was 80 ± 23. The most frequent symptoms were itching and posterior rhinorrhea. Multiple chemical sensitivity patients have an impairment in smell cognitive abilities (odour identification and forced choice, but not for detection) with increased smell hypersensitivity and poor quality of life.