Self-Reported Hypersensitivity to Smells: Objective Evidence for Hyposmia, not Hyperosmia

Area of Science:

• Neuroscience
• Otolaryngology
• Psychophysics

Background:

• Olfactory hypersensitivity, or hyperosmia, is a subjective complaint that may indicate underlying olfactory dysfunction.
• Previous research has not consistently differentiated between subjective complaints and objective olfactory capacity.

Purpose of the Study:

• To objectively compare olfactory function in patients reporting hypersensitivity versus those without such complaints using advanced psychophysical tests.
• To investigate potential contributing factors such as depression and other comorbidities.

Main Methods:

• A retrospective cross-sectional study was conducted at the Smell and Taste Center, University of Pennsylvania.
• Olfactory function was assessed using the University of Pennsylvania Smell Identification Test (UPSIT) and odor detection threshold tests.
• Data were analyzed using analyses of variance and chi-squared tests, including evaluation of the Beck Depression Inventory (BDI-II).

Main Results:

• Patients complaining of hyperosmia demonstrated significantly lower scores on both UPSIT and odor detection threshold tests compared to controls.
• A substantial proportion (70.95%) of individuals reporting hyperosmia exhibited objective evidence of hyposmia (reduced smell sensitivity).
• Individuals reporting hyposmia also showed elevated Beck Depression Inventory scores.

Conclusions:

• Objective psychophysical testing reveals that many patients complaining of olfactory hypersensitivity actually have diminished olfactory function.
• The discrepancy between subjective complaints and objective findings may be linked to altered smell perception, comorbidities like osmophobia, or psychological factors such as hypochondria.
• These results underscore the necessity of objective olfactory assessment for accurate diagnosis of chemosensory dysfunction and highlight the limitations of self-reported symptoms.