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Evidence-Based Reviews

How to help patients with olfactory reference syndrome

Delusion of body odor causes shame, social isolation.

Vol. 6, No. 3 / March 2007

Ms. A, a 21-year-old teacher, recalled always having been “sensitive,” but when she started her first job at age 19 she began to believe that she emitted an offensive odor. She experienced thoughts that she passed offensive flatus, her breath had a fecal odor, and people noticed and were offended.

Gradually Ms. A became more convinced of these distressing beliefs and began to think that she permeated fecal odor through her skin. She also became sure that colleagues were talking about her and that they complained about her “disgusting” smell.

Patients with olfactory reference syndrome (ORS) falsely believe they emit an offensive body odor. Prominent referential thinking—believing that other people perceive the odor—also is common. To introduce you to ORS, we discuss its clinical diagnosis and treatment based on our review of several hundred cases, including the largest reported series of patients with ORS.1-4

Box 1

Patient troubled by ‘a very bad odor…which came from his own person’

Olfactory reference syndrome (ORS) has been described around the world for more than a century. In 1891, Potts described a delusional 50-year-old man who “had been troubled for the past three months with smelling a very bad odor, which he likened to that of a ‘back-house,’ and which came from his own person. [He believed] this smell was so very strong that other men objected to working with him….”

Despite its long history, the syndrome’s prevalence is not well-established. ORS probably is underdiagnosed and more common than generally recognized:

  • In a tertiary psychiatry unit in London, 0.5% of 2,000 patients who were not systematically screened for ORS spontaneously reported ORS symptoms.
  • In a self-report survey of 2,481 students in Japan, 2.1% had been concerned with emitting a strange bodily odor during the past year.
  • In a study in a dental clinic in Japan, the majority of patients with a primary complaint of halitosis actually had “imaginary halitosis” (another term for ORS).

Source: References 1,2,5-9

Clinical features of ors

Ms. A quit her job and felt confident enough to work again only when she performed a 2-hour daily cleansing routine, doused herself in per-fume, and placed an incontinence pad in her underwear. Despite these precautions, she still thought her colleagues avoided her.

She always averted her mouth when speaking, held her hand in front of her mouth, and sat far from others and close to the door in meetings. She tried to keep meeting room doors open and believed that colleagues held their hands to their noses to “protect” themselves from her odor.

ORS symptoms are most often reported as beginning when patients are in their mid 20s, although some reports suggest onset during puberty or adolescence.4 In clinical series, the ratio of men to women is approximately 2:1.

Preoccupation. Individuals with ORS are preoccupied with the belief that they emit an unpleasant or offensive body odor (Box 1),1,2,5-9 most commonly:

  • flatulence, fecal, or anal odors
  • general body odor
  • halitosis
  • genital odors.1-3

Other perceived odors include sweat, armpit odor, sperm, urine, and malodorous hands and feet.1-3 Occasionally, the imagined odor resembles nonbodily smells, such as ammonia or detergent. The odor is perceived to emanate from corresponding body areas, such as the anus, skin, mouth, rectum, genitalia, feet, nose, or axillae.

Although most reports suggest that patients focus on one odor, some describe being concerned about several smells simultaneously or different odors over time.10,11

Referential thinking. As the syndrome’s name implies, many ORS patients have delusions of reference, falsely believing that other people perceive the odor.3 They misinterpret the behavior of others, assuming it is a reaction to how the patient smells (Box 2).2,3

They may misperceive comments (such as, “It’s stuffy in here”), receiving perfume or soap as a gift, or behaviors such as people sniffing, touching or rubbing their nose, clearing their throat, opening a window to get fresh air, putting a newspaper in front of their face, or looking or moving toward or away from the patient.1,3,5,7

Because they are ashamed, embarrassed, and concerned about offending others with their odor,13 many patients engage in repetitive and “safety” behaviors intended to check, eliminate, or camouflage the supposed odor (Box 3).1,3,7,12,14

Box 2

Delusion, hallucination, or both?

DSM-IV-TR classifies olfactory reference syndrome (ORS) as a delusional disorder, somatic type (the modern equivalent of monosymptomatic hypochondriacal psychosis). ORS also is mentioned in the text on social anxiety disorder. ORS may not be diagnosed if:

  • criterion A for schizophrenia has ever been met
  • or if symptoms are due to the direct physiologic effects of a substance or a general medical condition, such as a brain tumor or temporal lobe epilepsy.

Many patients report being able to smell the imagined odor, suggesting that they experience an olfactory hallucination. Pryse-Phillips described the olfactory hallucinations of her 36 ORS case patients as “a real and immediate perception… often perceived in the absence of other odors.”

ORS generally is regarded as delusional, with possible secondary illusional misinterpretations and referential thinking. ORS beliefs usually appear to be of delusional intensity, although some patients may have some—although limited—insight (that is, overvalued ideation).

Source: References 2 and 3

Functional impairment. Individuals with ORS often avoid other people or believe that others avoid them.12 They are typically embarrassed and worried that others will be offended by the smell. They may:

  • avoid activities such as dating
  • break off engagements
  • refuse to travel
  • move to another town
  • become housebound.3,7,10,12

Patients may change jobs repeatedly or avoid school or work3 because of shame and embarrassment, a belief that other people talk about the supposed odor, or the patient’s excessive preoccupations and time-consuming repetitive and safety behaviors.5,13,14

The distress and impaired functioning may lead to psychiatric hospitalization, depression, suicidal ideation, suicide attempts, and completed suicide.7,10,12,15 Pryse-Phillips studied 36 patients with ORS and reported:

  • nearly one-half (43%) experienced “suicidal ideas or action”
  • 2 (5.6%) committed suicide.3

Illness course. Most authors suggest that ORS is usually chronic, persisting for years if not decades, with possible worsening over time if patients do not receive appropriate treatment.11,15 In a 2-year follow-up study,3 ORS symptoms persisted relatively unchanged in 10 of 11 patients.

Some authors have questioned whether ORS can transform into schizophrenia, but others have found little evidence for this.3,6

Psychiatric comorbidity. Depression is mentioned most often in the literature.12,13 In Pryse-Phillips’ 36 ORS patients (who did not have a “primary” depressive disorder), depression symptoms tended to be severe.3 The depression generally is considered secondary to ORS, although Pryse-Phillips evaluated 50 additional patients with ORS symptoms whom she considered to have a “primary” depressive disorder.3 Other psychiatric comorbidities include bipolar disorder, personality disorder, schizophrenia, hypochondriasis, alcohol and/or drug abuse, obsessive-compulsive disorder (OCD), and body dysmorphic disorder.3,7,15 In a study of 200 individuals with body dysmorphic disorder, 8 had comorbid ORS.16

Diagnosing ORS

Clinical clues to ORS (Table 1) probably are not present in all patients and some are not specific to ORS. They appear to be common features of the illness, however, and may alert you to its presence. Our clinical impression is that many patients with ORS are secretive about their symptoms because they are ashamed of them. Thus, you need to be alert to clues and specifically inquire about ORS symptoms to detect its presence.

Criteria. DSM-IV-TR and ICD-10 lack specific diagnostic criteria for ORS, instead applying criteria for delusional disorder. One problem with this approach is that delusional disorder criteria specify that any co-occurring mood symptoms must be brief relative to the duration of the delusional periods. This requirement may not be valid when applied to ORS.

In our experience, some patients have protracted depressive symptoms that appear secondary to “primary” ORS symptoms, and another diagnosis—such as psychotic depression—does not appear to account for their symptoms.

We propose working diagnostic criteria for ORS (Table 2), which are similar to those proposed by Lochner and Stein17 and require empiric validation. Suggested questions for the patient interview (Table 3) can help you identify and diagnose ORS.

Differential diagnosis. Keep in mind that a false belief that one emits a bad smell may be a symptom of schizophrenia, and this would trump an ORS diagnosis if other schizophrenia symptoms are present. Some patients with severe depression may believe they smell bad as part of a nihilistic delusional belief system (such as in Cotard’s syndrome—nihilistic delusions in severe depression).

Whether to conceptualize a false belief about body odor as a symptom of depression or as ORS with comorbid or secondary depression may be unclear from case to case.

Table 1

Clinical clues to the presence of olfactory reference syndrome

Referential thinking. Interpreting actions of others—such as opening a window, moving away, putting a hand to their nose, or making comments related to odors—as evidence that the person smells offensive

Excessive attempts to ‘disguise’ the smell, such as washing routines, clothes changing, clothes laundering, or using abundant perfume, deodorant, mouthwash, mints, or other forms of camouflage

Other excessive and repetitive behaviors, such as checking for or asking other people for reassurance about the odor

Social anxiety or avoidance of social activities, relationships, work, school, or other daily activities

Requests for treatment for the perceived odor from dentists, gastroenterologists, proctologists, or other nonpsychiatric physicians despite a negative medical workup

Table 2

Working diagnostic criteria for olfactory reference syndrome


Persistent false belief that one emits a malodorous smell; this belief may encompass a range of insight and does not have to be delusional


The belief is time-consuming and preoccupies the individual for at least 1 hour per day


The belief causes clinically significant distress or results in significant impairment in social, occupational, or other important areas of functioning


The belief is not better accounted for by another mental disorder or a general medical condition

Table 3

Diagnosing ORS: Suggested questions for patient interview

  • Do you have concerns about the way you smell (your body odor)?
  • Do you believe that other people think you smell bad?
  • How much time do you spend each day thinking about your body odor?
  • Does your concern about how you smell upset you a lot?
  • Does your concern about the way you smell interfere with daily activities, such as your job, relationships, school work, or socializing? (Ask the patient about multiple and specific areas of functioning.)
  • Are there situations that you avoid (or wish you could avoid) because of the way you think you smell?

Treatment-seeking behavior

Ms. A consulted several proctologists and a dentist but was not convinced by their reassurance and continued to believe she “stank.” Her relationship with her boyfriend suffered because she continually asked for reassurance about how she smelled and avoided sexual intercourse because of her odor concerns.

Eventually she confronted her boss about her belief that her coworkers were complaining about her smell. Despite reassurance that she didn’t smell bad, she left her job.

Box 3

‘Safety’ and avoidance behaviors seen in olfactory reference syndrome

Excessive showering

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