OBJECTIVEThe study focus on the olfactory changes post upper respiratory infection, through observation of nasal mucosa and it's ultrastructural changes.

METHODSOlfactory test was performed by odor threshold and identification test (T&T olfactometry). The specimens of olfactory epithelium (OE) were obtained from 10 patients with anosmia or olfactory disorder post upper respiratory infection. All specimens were obtained under endoscope. Transmission electron microscope (TEM) was used to observe the ultrastructural changes of each group.

RESULTSUnder the TEM, the surface ultrastructure of the OE from patients showed following abnormal changes: (1) Normal epithelium structural characteristics maintained but clearance between cells appeared wider. (2) Olfactory vesicles reduced obviously, even if the olfactory vesicles existed, the olfactory cilia showed reduction. Some olfactory vesicles still existed, but the number of olfactory cilia reduced. Some olfactory vesicles changed their shape due to vacuolization. (3) Surface microvillus of the supporting cells disappeared. (4) The nuclei of supporting cell changed the shape or karyopyknosis, olfactory dendrites were shorter and wider than normal, and organelles reduced.

CONCLUSIONSThere is close relationship between ultrastructural changes and olfactory disorders post upper respiratory infection. Reduced olfactory vesicles, cilia and disappeared microvillus of the supporting cells are the main reasons for the patient's olfactory disorder.