Evidence-Based Reviews

How to help patients with olfactory reference syndrome

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Delusion of body odor causes shame, social isolation.



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


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