COVID-19 Induced Elimination of First Taste Phenomenon (P5-10.002)

Abstract

<h3>Objective:</h3> Correlation of First Taste Phenomenon elimination with COVID-19 infection <h3>Background:</h3> First Taste Phenomenon, whereby perception of flavor occurs at first bite and then dissipates is associated with chemosensory loss (Hirsch, 2018). Elimination of this Phenomenon associated with COVID-19 has not been described. <h3>Design/Methods:</h3> This 62 year old right handed man presented with upper respiratory tract infection induced chemosensory loss that resolved after treatment of 9 g of phosphatidylcholine. His smell declined to 50% of normal. Taste was lost but he retained his first taste phenomenon. He tested positive for COVID-19 presenting with loss of chemosensation which did not resolve despite treatment with nirmatrelvir/ ritonavir. Symptoms of COVID-19 improved after infection resolution, but First Taste Phenomenon never returned. <h3>Results:</h3> Neurological Abnormalities: Gustatory Testing: Taste threshold: Hypogeusia of 10–30% to sucrose. Electrogustometry Testing: left (L) posterior tongue: 34 (abnormal), right (R) posterior tongue: 34 (abnormal), L anterior tongue: 34 (abnormal), R anterior tongue: 30 (abnormal). Right palate: &gt;32 (abnormal), left palate: &gt;32 (abnormal). Taste Quadrant Testing: Front to back: decreased anteriorly to Sodium Chloride, Sucrose, Quinine Hydrochloride. <h3>Conclusions:</h3> The semiology of First Taste Phenomenon includes Classic First Taste Syndrome with full flavor of food followed by rapid, less than 1 minute, decrement in flavor of food (Hirsch, 2018). Retronasal smell inducing flavor perception as nidus to First Taste Syndrome (Djordjevic, 2004) could be eliminated after COVID-19 infection, which reduces retronasal smell, and induce perceived taste loss (Parma, 2020). This First Taste Phenomenon attributes to temporal decrement in saliva as a consequence of persisted mandibulation-reducing taste threshold sensitivity (Weiffenbach, 1995). COVID-19 worsens such hyposalivation (da Mota Santana, 2021). COVID-19 may eliminate first taste and cause CNS dysfunction via ACE type 2 taste receptor cells dysfunction, (Mastrangelo, 2021) and cytokine storm respectively (Hintschich, 2021). Those with preexisting chemosensory dysfunction, association of COVID on remaining chemosensation is warranted. <b>Disclosure:</b> Miss Birwatkar has nothing to disclose. Mrs. Kalita has nothing to disclose. Dr. Hirsch has nothing to disclose.