Two cases of olfactory reference syndrome responding to an atypical antipsychotic and SSRI

To the Editor

Olfactory reference syndrome (ORS) consists of a false belief that one emits an offensive odour, often accompanied by significant distress (Phillips et al., 2006). We report two cases initially misdiagnosed as social phobia.

Patient 1 was a 38-year-old man believing he emitted a faecal odour, secondary to frequent bowel motions. He detailed referential ideation that others were responding to the smell; intermittent olfactory hallucinations; auditory hallucinations of others whispering about him, and bizarre beliefs about how the smell was transmitted. He restricted his food consumption to minimise bowel motions, showered excessively, and isolated himself. After not responding to cognitive behavioural therapy (CBT), he was commenced on risperidone 3 mg nocte with improvement, and later on sertraline 50 mg mane for comorbid anxiety and low mood. On follow-up 2 months later, despite subsequently ceasing medications, the patient denied any ORS symptoms.

Patient 2 was a 19-year-old lady who believed others could smell fear in her body odour, experienced olfactory hallucinations, and had referential ideation of others responding to the smell. She avoided social situations, and engaged in excessive deodorant use and cleanliness. Upon commencing citalopram40 mg daily and CBT her mood and anxiety improved, but her beliefscontinued. She was commenced on aripiprazole, titrated up to 10 mg daily, with a complete resolution of her symptoms and significant improvement in her occupational functioning, maintained at 6-week follow-up.

Both our cases have features commonly seen in ORS, including referential ideation, safety behaviours, significant social impairment, and comorbid depression and anxiety. The existing literature of case studies favours serotonergic antidepressants as pharmacological treatment, with weaker evidence for the use of pimozide, which appears more efficacious than other antipsychotics but is unavailable in Australia. Our finding that both patients responded well to an antipsychotic/SSRI combination is in keeping with limited evidence that this approach appears promising. Interestingly, although there is some evidence for the use of behavioural therapy, neither of our patients responded completely to CBT. These outcomes also add to emerging cases suggesting atypical antipsychotics are beneficial in ORS (Phillips et al., 2006; Begum and McKenna, 2011).

Despite the reclassification in DSM-5 away from a delusional disorder to the obsessive compulsive disorder category (American Psychiatric Association, 2013), these two cases show that ORS can present as a psychotic disorder. Given the evidence suggesting ORS is a discrete syndrome not clearly falling within another diagnostic category, and, as our cases show, is often misdiagnosed, we think that calls to develop specific diagnostic criteria for further study are justified (Feusner et al., 2010).