Introduction

The olfactory reference syndrome (ORS) is an under-recognised type of delusional disorder that has been described for more than a century. It consists of a false belief that one emits an offensive body odour and is often accompanied by prominent delusions of reference and repetitive behaviours aimed at checking or reducing the perceived odour. ORS is associated with significant distress and impaired functioning, especially in the social realm. Many patients seek nonpsychiatric treatment from gastroenterologists, dermatologists, proctologists, dentists and other specialists; however, such treatments appear to be generally ineffective. In contrast, although data are limited, certain psychotropic medications and behavioural interventions are promising.

This chapter discusses ORS's history, clinical features, prevalence, treatment response, possible pathogenesis, nosological status and relationship to other psychiatric disorders, including mood disorders, schizophrenia, social phobia, and obsessive compulsive disorder (OCD).