ICD-116B22	OLFACTORY REFERENCE DISORDER (ORS) Olfactory reference disorder
ICD-10F45.8	Other somatoform disorders
DSM-5-TRF42.8	Other Specified Obsessive-Compulsive and Related Disorder (Olfactory Reference Syndrome)

1. Definition and nosology

Pathological Body Odor Disturbance (ORS) (ICD-11: 6B22 Olfactory Reference Disorder; DSM-5-TR: F42.8 Other Specified Obsessive-Compulsive and Related Disorder) — disorder characterized by obsessive belief about a non-existent or grossly over-appraised unpleasant odour emanating from the patient's body. Patient believes others condemn or embarrass him/her, exhibits compulsive washing, deodorant use, social avoidance behavior.

2. History

• Pryse-Phillips W. (1971) — term ‘olfactory reference syndrome’.
• DSM-IV — No separate category (Delusional Disorder as a somatic subtype).
• DSM-5 (2013) — OCD spectrum noted as a related disorder; but no separate code assigned.
• ICD-11 (2019) — first formal diagnostic category (6B22).

3. Epidemiology

• Prevalence: precise epidemiological data limited; based on clinical and review reports rare, but underdiagnosed (Phillips K.A., Menard W. Gen Hosp Psychiatry 2011).
• Onset: early adulthood (mean 20–25 years).
• Gender: approximately equal.
• Comorbidity: MDD, social anxiety, OCD, BDD, high suicide risk (suicidal ideation ~68%, attempts ~32% — Phillips K.A., Menard W. Gen Hosp Psychiatry 2011, n=20).

4. Aetiology and pathogenesis

• Genetic and neurobiological overlap with OCD and BDD.
• Insight is variable — sometimes at delusional level.
• Social-cultural factors — social stigma regarding body odor.

5. Clinical features

• Obsessive preoccupation with body odor (mouth, feet, armpits, genitals, general body) or breath odor.
• ‘Misreading’ others' reactions (referential ideas) — coughing, scratching nose, opening a window interpreted as ‘result of smell’.
• Compulsive behaviors — frequent washing, changing clothes, deodorant, perfume, oral hygiene, gum chewing, vigorous tooth brushing.
• Social avoidance — avoidance of work and school, social isolation.
• Compensatory behaviors — maintaining distance from others.

6. Diagnosis

6.1 Unified diagnostic criteria (ICD-11)

A. Persistent preoccupation that one's body emits an unpleasant odor or that there is a foul odor in the breath — which is either unnoticeable or minor to others.

B. The patient performs repetitive behaviors (washing, odor masking, skin checking) or mental acts (self-comparison with others) in response to obsession.

C. The preoccupation causes clinically significant distress or functional impairment.

D. Exclusion of substance or medical condition (real halitosis, hyperhidrosis, trimethylaminuria, metabolic diseases of odor substances).

Insight qualifier: good / moderate — poor / absent level.

6.2 Source-specific clarifications

• ICD-11 — official status as a separate category.
• DSM-5-TR — within ‘Other specified obsessive-compulsive and related disorder’.

6.3 Diagnostic algorithm

1. Clinical interview.
2. Medical and otolaryngological examination — excluding genuine halitosis, sinusitis, hyperhidrosis, gastrointestinal diseases.
3. Trimethylaminuria (TMAU) — urine trimethylamine test (rare genetic metabolic disorder, ‘fish odor syndrome’).
4. Insight level assessment.
5. Comorbidity and suicide risk (high!).

6.4 Differential diagnosis

7. Examination and assessment

• Medical examination — dental, ENT, gastrointestinal.
• TMAU test (urinary trimethylamine).
• Scale - not specific; adapted use of Y-BOCS.
• C-SSRS (high suicide risk).

8. Treatment

1. CBT — approach tailored to OCD/BDD; exposure (cessation of checking behavior, return to social situations), cognitive restructuring.
2. SSRI high dose — similar to OCD.
3. Augmentation — atypical antipsychotic (insight at delusional level).
4. Social rehabilitation.
5. Suicide risk monitoring.

Treatment methods

1. CBT (adapted for OCD/BDD) — Exposure + Response Prevention + Cognitive Restructuring.
2. SSRI High Dose — Similar to OCD; 8–12 weeks.

9. Prognosis

Evidence base is limited. Improvement with SSRIs + CBT; suicide risk monitored.

10. Myths and misconceptions

Myth 1: “The patient may genuinely smell bad — a psychiatric diagnosis cannot be made without prior medical examination”

Evidence: correct — medical causes (halitosis, hyperhidrosis, TMAU) must be definitively excluded; but if no medical cause and obsessive preoccupation persists, clinical condition is olfactory reference disorder.

Myth 2: “Frequent washing and deodorant use will solve the problem”

Evidence: Compulsive behaviors provide short-term relief but intensify the disorder; skin irritation, social impairment increase.

Myth 3: “The patient has a simple self-esteem problem”

Evidence: Clinical impairment; suicide risk is high (suicidal ideation ~68%, attempts ~32%); medical intervention required.

Myth 4: “Only an antipsychotic is effective because it is a delusion”

Evidence: insight variable; SSRI high dose + CBT first line; antipsychotic augmentation only at delusional level.

11. Sources

1. WHO. ICD-11. 6B22 Olfactory reference disorder. 2024.
2. APA. DSM-5-TR. 2022.
3. Phillips K.A., Menard W. Olfactory reference syndrome: demographic and clinical features of imagined body odor. Gen Hosp Psychiatry 2011;33(4):398–406.
4. Pryse-Phillips W. An olfactory reference syndrome. Acta Psychiatr Scand 1971;47(4):484–509.