Unique and shared patterns of chemosensory dysfunction distinguish chronic COVID-19 and aspirin-exacerbated respiratory disease.

BACKGROUND

Persistent chemosensory dysfunction (CSD) occurs in both COVID‑19 and aspirin-exacerbated respiratory disease (AERD). The similarities and differences in the chemosensory experiences of these 2 conditions remain undefined and poorly understood.

OBJECTIVE

To compare qualitative and quantitative chemosensory alterations and quality-of-life impact in individuals with COVID-19-associated vs AERD-associated CSD.

METHODS

Participants from the Brigham and Women's Hospital COVID-19 CSD registry (n = 406) and the Brigham and Women's Hospital AERD registry (n = 389) completed online questionnaires assessing CSD characteristics and sinonasal disease-related quality of life.

RESULTS

COVID‑19 CSD showed a distinct qualitative phenotype. Overall, 60% of COVID‑19 participants reported that odors smelled different from how they recalled them, vs 19% with AERD (P < .001). Unpleasant odor perception was experienced by more than 20% of COVID‑19 participants, but by less than 5% of AERD participants. COVID‑19 CSD involved selective impairment and unpleasant distortion of sour, bitter, and umami tastes, whereas AERD exhibited a uniform quantitative reduction across taste modalities. Flavor distortions, particularly for foods with bitter or fatty components (eg, coffee, chocolate, and nut butter) and chemesthetic flavors (eg, spicy, mint, alcohol, garlic, and ginger), were significantly more common in COVID‑19 CSD (average: 25%) than in AERD (average: 0%). Both conditions were associated with impaired quality of life, including odor and food safety-related concerns.

CONCLUSION

Both COVID‑19 CSD and AERD cause profound chemosensory disruption. However, COVID‑19 CSD is distinguished by marked qualitative distortions in smell, taste, flavor, and chemesthesis. In contrast, AERD CSD reflects a more generalized sensory reduction. Incorporating these characteristic sensory profiles into routine evaluations may improve diagnostic accuracy and guide patient counseling for ongoing chemosensory care.