ABSTRACT
Patients can present with reduced or absent sense of smell for a variety of reasons. An algorithm for investigation is provided in the Appendix
The sense of smell is difficult to test objectively. Olfactory evoked responses have been measured, but are not in routine clinical use. The test most widely used for evaluation is the UPSIT (University of Pennsylvania Smell Identification Test) (Figure 9.1). This has been validated and the format, which involves scratch and sniff testing with forced choice from four possible answers for each odour, allows differentiation of malingerers. The result is given as the number of smells correctly identified out of 40 and the patient is assigned to normosmia, hyposmia or anosmia according to age based on a graph derived from hundreds of subjects. Unfortunately, the UPSIT test is expensive, has to be imported and contains many odours
which are specifically American, thus very few patients in the United Kingdom score full marks.
