(A237) Prognosis of Chemosensory Recovery Among Long COVID-19 Patients – 3 and 6 Month Follow-ups

Introduction: Chemosensory dysfunction is a hallmark symptom of COVID-19 infection, with many patients experiencing symptoms beyond initial infection. This ongoing study aims to capture the timeline in chemosensory recovery following post-acute sequelae of SARS-CoV-2 infection (PASC).

Methods: This preliminary analysis that started in 2023 includes 23 patients (30-74 years old, median: 56) who contracted COVID-19 from 3/2020 to 11/2023, 8-51 months (median: 31) prior to the initial visit. All then completed a 3-month follow-up, and 12 completed a 6-month follow-up which took place in the lab testing room. Patients received objective testing of 1) smell function using the 9-Item NIH Toolbox Odor Identification (ID) Test, detection threshold (ODT) to phenyl-ethyl alcohol (PEA), and retro-nasal flavor identification (candy test); 2) taste function using the modified NIH toolbox.

Results: Patients self-reported a high prevalence of smell (78%) and taste (65%) losses. 78% confirmed objective smell loss, while only 20% confirmed objective taste loss. At 3-month follow-up, patients exhibited significant improvements in objective smell (Odor ID, p=0.0139) function but not objective taste (NIH Toolbox, p=0.107), yet the number of patients exhibiting objective chemosensory losses remained high (smell 43%, taste 22%). From 3- to 6-month follow-up, patients showed significant decline in objective taste (p=0.0496) function.

Conclusions: These findings suggest significant fluctuations in chemosensory function following COVID-19 infection, with prognosis prolonged and uncertain, and self-report being unreliable, especially for taste loss. Future work will continue to evaluate smell and taste for a larger sample size and longer time duration.