Chronic sinusitis and anosmia: pathologic changes in the olfactory mucosa.

Area of Science:

• Otorhinolaryngology
• Pathology
• Olfactory Neuroscience

Background:

• Chronic rhinosinusitis (CRS) is frequently associated with olfactory dysfunction, including anosmia.
• The precise mechanisms linking CRS to olfactory loss remain incompletely understood, with airflow obstruction and mucosal inflammation being primary hypotheses.

Purpose of the Study:

• To histologically evaluate olfactory mucosal changes in patients with CRS.
• To correlate these histological findings with clinical olfactory function assessments.

Main Methods:

• A prospective study involving 30 patients undergoing sinus surgery for CRS.
• Olfactory biopsies were obtained during surgery and histologically graded for inflammation.
• Olfactory function was assessed using the University of Pennsylvania Smell Identification Test (UPSIT).

Main Results:

• Nineteen patients had evaluable olfactory mucosa; 11 had respiratory or indeterminate mucosa.
• Nine patients showed normal olfactory mucosa and normal olfactory function (UPSIT > 35).
• Ten patients exhibited pathological changes (lymphocytes, macrophages, eosinophils) in olfactory mucosa; 7 of these had olfactory deficits (UPSIT < 35).
• Three patients had normal function despite moderate inflammation.
• Olfactory mucosa demonstrated inflammatory responses similar to respiratory mucosa in CRS.

Conclusions:

• Inflammatory changes within the olfactory mucosa likely contribute to olfactory deficits in CRS patients.
• These findings suggest that direct mucosal inflammation, not just airflow alteration, plays a significant role in CRS-related anosmia.