Proposed classification scheme for quantitative olfactory function alterations

Given the need for a clinical classification far daily patient examinations to refer to each type of quantitative alteration in the sense of smell, we have created a topographic classification of such alterations, establishin g groups to distinguish among patients with decreased or total loss of olfa ction. Because the classification is based on the diagnosis of the differen t causes of anosmia, it implicitly includes etiologic and topographic consi derations. We have established 3 main groups on the basis of the site of th e causal lesion: conduction, sensorineural, and mixed anosmias. In addition , within the sensorineural anosmias, we distinguish between the epithelial, retroepithelial, and central anosmias.