Chronic sinusitis and anosmia: Pathologic changes in the olfactory mucosa

Objectives: To evaluate histological changes in the olfactory mucosa of patients with chronic rhinosinusitis. These results are analyzed in light of current understanding of the pathophysiology of anosmia secondary to nasal and sinus disease. Study Design: Prospective study of olfaction on patients undergoing sinus surgery for the management of chronic rhinosinusitis. Methods: Thirty patients, aged 22 to 39 years, underwent olfactory biopsy at the time of surgery with evaluation by a pathologist. Inflammatory changes were graded as mild (normal), moderate, or severe. Clinical olfactory function was evaluated using the University of Pennsylvania Smell Identification Test (UPSIT). The results correlated with the degree of olfactory dysfunction. Results. Of the 30 patients 19 had unequivocal olfactory mucosa in the biopsy specimen. Eleven had only respiratory or indeterminate mucosa. Nine patients demonstrated normal olfactory mucosa and normal olfactory function (UPSIT >35). Ten patients demonstrated pathological changes in the olfactory mucosa with an influx of lymphocytes, macrophages, and eosinophils. Of these 10 patients, 7 had olfactory deficits as determined by UPSIT. The remaining three patients had normal olfactory function despite moderate chronic inflammation. These studies indicate that the olfactory mucosa is capable of mounting an inflammatory response similar to that seen in the respiratory mucosa of patients with chronic sinusitis. These data suggest that the olfactory deficits in these patients may be the result of inflammatory changes within the olfactory mucosa in addition to any alteration in airflow to the olfactory cleft.