Olfactory reference disorder

INTRODUCTION — 

Olfactory reference disorder (ORD), also known as olfactory reference syndrome, consists of persistent preoccupation with emitting a foul or offensive body odor that, in reality, is unnoticeable or only slightly noticeable to other people. Patients with ORD erroneously think that they smell bad (eg, that they "stink" or "smell disgusting"). The preoccupation with perceived body odor triggers repetitive behaviors (eg, checking for body odor) and causes clinically significant distress and/or clinically significant impairment in functioning. (See 'Assessment and diagnosis' below.)

Patients with ORD may present not only to mental health professionals but also to dermatologists, dentists, otolaryngologists, gastroenterologists, proctologists, primary care clinicians, pediatricians, surgeons, obstetrician/gynecologists, and others.

ORD has been described worldwide since the 1800s [1-5]. It is widely conceptualized as being closely related to body dysmorphic disorder (BDD) and obsessive-compulsive disorder (OCD) [6-10], and, in traditional Japanese psychiatry, to social anxiety disorder ("taijin kyofusho") [11]. It has historically also been considered by some to be a psychotic disorder [12]. Various historical terms (no longer used) include olfactory delusional syndrome, olfactory paranoid syndrome, delusional halitosis, imaginary halitosis, monosymptomatic hypochondriacal psychosis, and bromidrosiphobia [1-3].

This topic, and the associated algorithm, describe the epidemiology, clinical features, diagnosis, and treatment of olfactory reference syndrome (algorithm 1). Related topics such as BDD, OCD, and bromhidrosis are discussed elsewhere. (See "Body dysmorphic disorder: Clinical features" and "Body dysmorphic disorder: Choosing treatment and prognosis" and "Obsessive-compulsive disorder in adults: Epidemiology, clinical features, and diagnosis" and "Obsessive-compulsive disorder in adults: Treatment overview" and "Bromhidrosis".)

EPIDEMIOLOGY — 

The prevalence of olfactory reference disorder (ORD) is not clear, but it is widely considered to be underdiagnosed and more common than generally recognized [6,13-15].

●In student-based surveys in Japan and China, the percentage of students with reported symptoms that might reflect ORD were 2.1 and 2.4 percent, respectively [16,17].

●In a psychiatric inpatient unit in London, United Kingdom, 0.5 percent of 2000 patients spontaneously reported ORD symptoms [18]. This was likely an underestimate because patients were not systematically screened for ORD.

The male to female ratio in literature reviews is approximately 1.6 to 2:1 [1,3], although subsequent studies report a gender ratio of 1:1 [12] or 60 percent female [19]. Most patients are single [1,8,19].

PATHOGENESIS — 

The pathogenesis of olfactory reference disorder (ORD) is not firmly established. Multifactorial etiologies including biologic (eg, genetic), psychologic, psychosocial, and cultural factors are suspected [1,9,14]. As examples:

●Stressful life events, chronic teasing, psychologic trauma, and societal taboos regarding body odor have been postulated to contribute [1,14,20].

●Case reports of single-photon emission computed tomography (SPECT) imaging found decreased perfusion in the left frontotemporal region [21,22], with multiple additional perfusion defects in one report [21].

Most patients report actually smelling their body odor, which raises the possibility that they may have enhanced odor perception [19,20]. However, preliminary findings suggest that misperception of body odor in ORD does not reflect more accurate recognition of, or hypersensitivity to, body odor [23,24]. ORD symptoms may instead reflect olfactory hallucinations or, in some cases, misjudgment of others' behavior (referential thinking).

From an evolutionary perspective, ORD behaviors such as excessive showering and tooth brushing, done to eradicate perceived body odor, have similarities to excessive grooming behaviors in animals that aim to remove odors and thereby avoid predators [25,26]. Conceivably, such processes could go awry and contribute to the development of ORD. Because ORD has similarities to body dysmorphic disorder, obsessive-compulsive disorder, and social anxiety disorder and is often comorbid with them, it may share aspects of these disorders' etiology/pathophysiology [1,9-12,19,21].

CLINICAL FEATURES

Onset and course — Olfactory reference disorder (ORD) most often starts during adolescence or early adulthood [8,19]. In a review of 84 case reports, onset was less than age 20 in nearly 60 percent [3]. Symptom onset can be acute or gradual [1,19]. The disorder is often associated with major depressive disorder and suicidality.

Without appropriate treatment, ORD often persists for years if not decades [1,6,27,28]. In a cross-sectional study, 84 percent of 20 participants reported a chronic course of illness, with more than half reporting symptom worsening over time [19]. In a two-year follow-up study, ORD symptoms persisted relatively unchanged in 10 of 11 patients [20]. Some patients report persistence of the same body odor concerns over time, and a similar proportion report that new body odors develop over time [19]. It is not known whether certain clinical features predict a worse course of illness. ORD does not appear to be a prodrome to other illnesses, such as schizophrenia [20].

Characteristic symptoms — The characteristic symptoms of ORD include the following:

Preoccupation with body odor — The body odor preoccupations are persistent, intrusive, unwanted, and difficult to resist or control, occurring, on average, for three to eight hours a day [6,19]. Patients may describe their body odor with terms such as "stinky," "horrible," "disgusting," or "revolting."

Whether the preoccupation reflects actual self-detection of an odor is uncertain [3,19,20]. In reality, the odor is unnoticeable or only slightly noticeable to others. If the person does emit a slight body odor, their concern is markedly disproportionate to the odor [6]. Healthy controls do not rate the sweat of people with ORD as significantly more disgusting than their own sweat [29]. In cultures that emphasize shame, the patient's concern may focus on a fear of offending others with their body odor [6,30].

The preoccupations are distressing. This may be due to their focus on perceived unacceptability of the self to others and the inaccurate belief that other people mock, reject, and avoid them because of how they smell (ie, referential thinking) [6].

Commonly perceived body odors are [1,3,8,13,14,19,20]:

●Halitosis (bad breath)

●Sweat

●Flatulence/fecal odor

●Urine

●Genital odor

Other sources include the feet, head, scalp, and under the breasts [3,19]. Occasionally, the odor resembles nonbodily smells, such as ammonia, garbage, detergent, or rotten onions, which are perceived to emanate from the patient's body (usually in addition to typical body odor perceptions) [1,3,19]. Some patients are preoccupied with only one odor, whereas many are preoccupied with several odors simultaneously or with emitting different body odors over time [1,8,19].

Repetitive behaviors — Excessive repetitive behaviors (ie, compulsions, rituals) are a core feature of ORD [1,19,20]. Nearly all patients with ORD perform excessive repetitive behaviors, with an average of four different behaviors during the course of the illness [19]. Body odor concerns and the belief that one is therefore unacceptable to others triggers emotional distress (eg, depressed mood, anxiety, shame), which in turn triggers compulsive repetitive behaviors. These behaviors aim to reduce distress by eliminating, preventing, checking, or obtaining reassurance about the perceived smell. The time-consuming repetitive behaviors are usually difficult to resist or control and are not pleasurable [19]. Most behaviors are observable by others, but mental rituals (eg, comparing one's own body odor to that of other people) may also occur [19].

The following are common repetitive behaviors. Their presence suggests a need for further evaluation for ORD [1,3,6,19,20,31] (see 'When to suspect olfactory reference disorder' below):

●Smelling/checking oneself for body odor

●Smelling/checking one's clothes for body odor

●Comparing one's body odor to that of other people

●Excessive showering, bathing, or other body washing to remove perceived body odor

●Excessive use of the toilet (eg, to check for anal seepage)

●Excessive tooth brushing to reduce perceived halitosis

●Frequent clothes changing to remove clothes that were in contact with the odor and are thus believed to be malodorous

●Frequent clothes laundering

●Eating a special diet to try to eliminate perceived body odor (eg, halitosis or flatulence)

●Seeking reassurance from others about how one smells

Suicidality, depression, emotional distress — On average, ORD symptoms cause moderate to severe distress [19], and they can trigger suicidal thinking and suicide attempts [1,8,27,31-34].

In studies that systematically assessed patients with ORD for suicidal ideation (two studies; n = 34) approximately two-thirds had a history of suicidal ideation [8,19]. In one study, 47 percent of the total sample (n = 20) reported suicidal ideation that they attributed primarily to ORD symptoms, 32 percent had attempted suicide, and 16 percent stated that the attempted suicide was primarily due to ORD symptoms [19]. Other studies have reported similar findings [8,20]. (See 'Severe olfactory reference disorder' below.)

Death by suicide has been reported [27]. In a study of 36 patients, 5.6 percent died by suicide during an average follow-up period of 17 months, yielding a markedly elevated suicide rate [20]. The suicides appeared to be due to ORD.

ORD may lead to depression, which can be severe [20], and psychiatric hospitalization [18,32]. In one study, 53 percent of 20 patients had been psychiatrically hospitalized, and one-third of the entire sample had been psychiatrically hospitalized primarily because of ORD symptoms [19]. Greater ORD severity is significantly associated with poorer psychosocial functioning [19].

Patients are usually ashamed and embarrassed by their perceived foul body odor, and they feel self-conscious around other people [1,6,20,30]. Scores on measures of fear of negative evaluation, social anxiety, and social distress are significantly higher than for healthy controls and similar to those of people with social anxiety disorder [12].

Patients with ORD also have greater disgust sensitivity, tendency to experience disgust, and self-disgust than healthy controls [29].

Functional impairment — ORD typically impairs psychosocial functioning, sometimes to a debilitating degree. It may be difficult for patients to work, attend school, or participate in social activities because they believe that they smell bad [1,14,18,20,31,32]. If functioning is maintained, this often occurs only through significant additional effort [6]. In one study, current interference in psychosocial functioning due to ORD was severe or extreme and disabling in more than half of patients, and mean scores on the Global Assessment of Functioning scale reflected "serious" symptoms or "serious" functional impairment [19].

Other clinical features

●Avoidance behaviors – Avoidance behaviors are common [1,8,19,20,32]. Scores on measures of social avoidance are similar to those of patients with social anxiety disorder [12]. Patients may avoid work, school, social interactions, and other important activities because the body odor preoccupations and repetitive behaviors are so time consuming and distracting. Others may do so because they experience ideas or delusions of reference, fear offending others with their smell, or feel ashamed, self-conscious, and embarrassed about the perceived odor [1,30]. More subtle avoidance behaviors include moving as little as possible to avoid spreading the supposed odor, averting one's head, covering one's mouth, or sitting far from other people [1,3,13,18-20,31,32].

In one study, three-quarters of patients had experienced periods of avoiding most social interactions because of ORD, and nearly 50 percent reported periods of avoiding most occupational, academic, and/or other important role activities because of ORD [19]. In other studies, 40 percent of individuals with ORD have been completely house-bound for at least one week and only 3 percent of patients were socially active [19,20].

●Referential thinking – This consists of inaccurate beliefs that gestures, comments, or other environmental cues are directed at oneself. As an example, if the patient receives soap or cologne as a gift; hears a comment such as "It's stuffy in here," or "Let's get some fresh air"; or observes someone opening a window, sniffing, touching their nose, frowning, clearing their throat, coughing, or moving away from them, they mistakenly believe that their foul body odor is the reason for the comment or behavior [3,6,13,18-20,31,32]. In addition, nearly all patients inaccurately believe that other people can smell their body odor, sometimes from a great distance (which does not necessarily involve referential thinking) [19,20].

●Camouflaging behaviors – Nearly all patients attempt to camouflage (mask), alter, or prevent the perceived body odor, which may be a clue to the presence of ORD. The following are commonly used [1,6,8,19,20]:

•Perfume, cologne, other fragrance, or powder

•Deodorant or soap

•Gum, mints, mouthwash, or toothpaste

•Layers of clothes

Less common examples are smoking, putting cornstarch on one's feet, wearing heavy underwear, or frequently spraying oneself and the room with an alcohol solution or fragrance to mask the perceived smell [13,19,20,32]. Camouflaging can be done so excessively that the patient strongly smells like the camouflaging substance (eg, perfume). Camouflaging is avoidant in nature (ie, a safety behavior), but when it occurs frequently during the day (eg, reapplying deodorant) it can be considered a repetitive behavior.

●Limited insight – ORD beliefs are usually characterized by absent insight (ie, delusional thinking) [1,19,20]. Most patients are completely convinced that they truly do emit a noticeable, foul odor. This is consistent with the high proportion who report actually smelling the odor themselves (ie, who have olfactory hallucinations). Only approximately 15 percent recognize that their belief about the body odor may be inaccurate [19]. Poorer insight is significantly associated with greater ORD severity [19]. Poor or absent insight can make it difficult to engage patients in psychiatric treatment, and many seek surgery and nonpsychiatric medical treatment instead [35].

Comorbid psychiatric illness — Lifetime comorbidity of other psychiatric disorders has been reported as follows [1,8,19,20,32]:

●Major depressive disorder (85 percent) – Studies suggest that the development of major depression may be due to suffering that ORD causes [19,20,32]

●Social anxiety disorder (65 percent)

●Substance use disorder (65 percent)

●Obsessive-compulsive disorder (30 percent)

●Body dysmorphic disorder (30 percent)

ASSESSMENT AND DIAGNOSIS

When to suspect olfactory reference disorder — Olfactory reference disorder (ORD) is often overlooked in clinical practice. We specifically inquire about ORD symptoms, particularly when possible clues to the disorder are present (eg, ideas or delusions of reference, repetitive ORD behaviors, camouflaging behaviors, social avoidance). Patients may be reluctant to spontaneously reveal their body odor concerns because they feel embarrassed and ashamed. In addition, poor or absent insight (ie, believing that the odor has a physical rather than a psychiatric cause) may cause underreporting of symptoms to mental health clinicians [6,15,36].

Assessment — A comprehensive medical history and physical examination investigating the cause of symptoms is undertaken. A complete psychiatric history and mental status examination is also undertaken. Emphasis is placed on depressive symptoms and suicidality. We assess for suicidal ideation in all individuals with ORD. Laboratory tests are obtained based on the history and examination. We are vigilant to review the patient's history and obtain collateral information with permission [1-3,6,35].

●Assessing persistent preoccupation, repetitive behaviors, and nonmental health treatment – To identify preoccupation with body odor, we ask the individual the following questions.

•"Are you very worried that you smell bad?"

•"What are you concerned about?"

•"If you add up all the time you spend, how much time would you estimate that you spend each day thinking about body odor?"

•"Is there anything you feel an urge to do over and over again in response to your body odor concerns?" (Offer examples such as smelling oneself for body odor, excessive body washing or showering, and excessive toothbrushing or use of mouthwash (if halitosis is a concern).

•"Have you had prior surgical, dental, or nonpsychiatric medical treatment for perceived body odor or are you planning any?"

•"Have other clinicians recommended for or against such treatment?"

Additionally, we ask about expectations for surgery or any other intended nonpsychiatric treatment. Some patients with ORD may have unrealistic expectations (eg, that they will get a girlfriend if they have a tonsillectomy for perceived halitosis).

We observe patients' behavior when they come into the office for an evaluation, observing for unusual requests for appointment times to avoid being around other people, or asking to wait outside to avoid scrutiny.

●Assessing for level of distress and functional impairment – At least moderate distress or moderate impairment in functioning due to ORD are consistent with the diagnosis. If functioning is maintained, determine whether it is only through significant additional effort. We evaluate the level of distress and functioning by asking the following questions.

•"How much distress do these concerns cause you?" (We ask specifically about the patient level of anxiety, depression, shame, self-consciousness, and suicidal ideation.)

•"Do these concerns interfere with your life or cause problems for you in any way?"

•"Do your symptoms affect your functioning at work, school or in other ways (eg, managing household, maintaining relationships, intimacy, family)?"

•"Do your symptoms cause avoidance of people or situations?"

●Assessment of level of insight – We find it helpful to determine level of insight because this may reflect the patient's willingness to receive psychiatric treatment. The Brown Assessment of Beliefs Scale (BABS) is a seven-item semistructured clinician-administered measure that assesses insight during the past week in a range of disorders [37]. To determine level of insight without use of the BABS, we elicit a global belief about the perceived odor (eg, "I stink") and ask, "how convinced are you that you smell (fill in with patient's descriptor)?"

●Rule out other causes of the symptoms – We differentiate ORD from other disorders (eg, psychiatric disorders, medical or neurologic disorders) that may cause similar symptoms. (See 'Differential diagnosis' below.)

Diagnosis — We diagnose ORD in individuals with persistent preoccupation with the belief that they emit a foul or offensive body odor that is unnoticeable or only slightly noticeable to others. In response to this preoccupation, the individual engages in repetitive and excessive behaviors (eg, checking, seeking reassurance), and the symptoms cause significant distress or significant impairment in social, occupational, or other important areas of functioning [38]. The American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR) classifies ORD as an example of an "Other Specified Obsessive-Compulsive and Related Disorder" in the chapter of Obsessive-Compulsive and Related Disorders [38]. ORD is classified as a separate codable disorder in the International Classification of Diseases, 11^th Revision (ICD-11) in the chapter of "Obsessive Compulsive or Related Disorders" [6].

●Assessing severity of ORD – We use the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) modified for ORD, a 12-item, semistructured, clinician-administered measure, to assess ORD severity after the diagnosis of ORD has been made [19]. This scale is similar to the Y-BOCS for obsessive-compulsive disorder and the Y-BOCS modified for body dysmorphic disorder [39,40].

In clinical practice, symptom severity over time can be quickly assessed without use of a scale by determining total time per day preoccupied with body odor, distress due to body odor concerns, and interference due to body odor concerns. For the latter two items, a scale of none, mild, moderate, severe, and extreme can be used.

DIFFERENTIAL DIAGNOSIS — 

We rule out other medical or dental conditions that may cause slight body odor or olfactory hallucinations prior to diagnosing olfactory reference disorder (ORD) [10,15,20]. ORD is distinguished from normal concerns with body odor by the degree of preoccupation, distress, and interference in functioning that the concerns cause [6]. We differentiate ORD from the following disorders, any of which can be comorbid with ORD:

●Psychiatric disorders

•Body dysmorphic disorder – In body dysmorphic disorder, obsessions/preoccupations and repetitive behaviors focus on perceived defects in one's physical appearance, not perceived body odor.

•Obsessive-compulsive disorder – Unlike obsessive-compulsive disorder, the obsessions/preoccupations and repetitive behaviors of ORD focus specifically on the inaccurate belief that one emits a foul or offensive body odor.

•Social anxiety disorder – Patients with ORD feel self-conscious, fear rejection and humiliation, and avoid social situations because they believe that they smell bad.

In contrast, patients with social anxiety disorder avoid social situations because they are concerned that they will act in a way, or show anxiety symptoms, which will be negatively evaluated by others.

•Major depressive disorder – Depressive symptoms are common in patients with ORD [3,19,20], but ORD is additionally characterized by preoccupation with emitting a foul or offensive body odor, related repetitive behaviors, and other ORD symptoms.

•Schizophrenia and other psychotic disorders – In ORD, delusional beliefs and delusions of reference focus specifically on perceived body odor, and related compulsive behaviors are usually present. Characteristics such as nonbody odor hallucinations, grossly disorganized speech or behavior, and negative symptoms are absent.

Patients with schizophrenia who have olfactory hallucinations usually do not complain about them or perceive the smell to emanate from their own body, and they do not feel embarrassed by the perceived odor or try to remove it [20,41].

•Avoidant personality disorder – If social inhibition, feelings of inadequacy, and hypersensitivity to negative evaluation are attributable to ORD symptoms, ORD is diagnosed rather than avoidant personality disorder.

•Agoraphobia – If places or situations (eg, public transportation) are avoided because the patient believes that they emit a foul or offensive body odor, ORD is the more accurate diagnosis.

●Neurologic and other medical disorders – Clinical features may suggest consideration of a neurologic/medical etiology.

As an example, in an individual who reports nonbodily odors such as burning rubber (especially without concurrent concern about body odor), a perceived odor that the patient does not experience as emanating from their body (eg, burning tires, sewer odors), auditory or gustatory hallucinations, rising epigastric sensations, automatisms, or brief paroxysmal odor perception, and absence of classic features of ORD (eg, referential thinking, avoidance behaviors) we might consider temporal lobe epilepsy [6,15,20,42].

We distinguish ORD from other disorders that may present with similar symptoms (eg, temporal lobe epilepsy, migraine) by taking a careful history (including collateral history when available), physical examination, and ancillary tests as indicated (eg, electroencephalogram in suspected temporal lobe epilepsy). While imaging, neuropsychologic testing, and other tests are not currently used to diagnose ORD, we use them, if indicated for a specific patient, to rule out other disorders that may have similar presentation. (See "Nonepileptic paroxysmal disorders in adolescents and adults", section on 'Migraine' and "Focal epilepsy: Causes and clinical features" and "Nonepileptic paroxysmal disorders in adolescents and adults", section on 'Hallucinations'.)

Trimethylaminuria, also known as fish odor syndrome or fish malodor syndrome, is a rare metabolic disorder caused by deficiency or dysfunction of the hepatic enzyme flavin-containing monooxygenase 3 (FMO3) [43]. In these cases, the odors are typically apparent to others besides the patient. Other errors of metabolism that may lead to abnormal odors and their diagnosis are reviewed elsewhere. (See "Inborn errors of metabolism: Epidemiology, pathogenesis, and clinical features", section on 'Abnormal odors'.)

TREATMENT — 

Treatment with certain medications and cognitive-behavioral therapy (CBT) that is tailored to olfactory reference disorder (ORD) appear to improve symptoms of ORD (algorithm 1). Other treatments appear to be ineffective for most individuals. (See 'Treatments with minimal or no support' below.)

Principles and goals — Before starting treatment, we provide psychoeducation and the rationale for treatment.

Most patients have limited or no insight regarding their perceived body odor, and they may doubt that psychiatric treatment can be helpful [15,19,20]. Others may be relieved to learn that they have a known treatable disorder that can be helped. We do not minimize the nature of the symptoms or the patient's belief, but we note that there is a mismatch between their perception and that of others, and that other people do not actually perceive the odor [36]. We express empathy for their suffering and help them to overcome their symptoms. With the patient's permission, we often involve family members in the treatment (parental/guardian involvement is required for treatment of minors). Motivational interviewing techniques may be needed. (See "Overview of psychotherapies", section on 'Motivational interviewing'.)

The goal of treatment is symptom remission, with a particular focus on body odor obsessions, repetitive behaviors, and ORD-related distress and functional impairment.

Mild or moderate olfactory reference disorder — Initial treatment for mild ORD (eg, ORD Yale-Brown Obsessive Compulsive Scale [Y-BOCS] score of 20 to 23, Clinical Global Impression-Severity [CGI-S] score 3) or moderate ORD (eg, ORD Y-BOCS score of 24 to 30, CGI-S score of 4) is guided by severity of the disorder. However, patient preference is considered in all treatment decisions. Additionally, we consider treatment history, comorbidity, pregnancy and lactation status, and side effects of treatments.

Initial treatment choices include pharmacologic management with a selective serotonin reuptake inhibitor (SSRI), CBT tailored to ORD, or both. However, these treatments have not been directly compared. We typically agree to provide combined modality treatment with antidepressant medication and psychotherapy for patients who express an interest in combined treatment.

●Preference for pharmacotherapy – For patients with mild or moderate ORD for whom pharmacotherapy is the preferred initial choice we prefer an SSRI, such as fluoxetine. While the serotonin reuptake inhibitor tricyclic antidepressant clomipramine also appears effective, we prefer to use an SSRI as initial management as they are typically better tolerated and easier to prescribe. (See "Tricyclic and tetracyclic drugs: Pharmacology, administration, and side effects" and "Selective serotonin reuptake inhibitors: Pharmacology, administration, and side effects".)

Our clinical experience suggests that doses needed to successfully treat ORD are similar to those used to treat other disorders with prominent obsessions, such as obsessive-compulsive disorder and body dysmorphic disorder (BDD) [44,45]. Although some patients improve with relatively low doses (eg, fluoxetine 20 or 40 mg/day), many do not. Somewhat lower initial and maximum doses are more suitable for youth and older adult patients. Due to cardiac conduction concerns, we avoid citalopram in all patients and escitalopram in those over 65 years. Doses of SSRIs used in the treatment of ORD are shown on the table (table 1).

Our preference is to treat with a therapeutic trial of the initial medication prior to making further treatment decisions. We consider a therapeutic trial to be 12 to 16 weeks, with at least four weeks at the target dose (if needed and tolerated) before determining whether the medication is beneficial.

In our clinical experience, monotherapy with an SSRI, often at a high dose, often effectively treats ORD, including patients with delusional ORD beliefs. Although use of SSRIs as monotherapy for delusional beliefs may sound counterintuitive (because antipsychotics are typically used for disorders characterized by delusional beliefs), SSRI monotherapy is often efficacious for patients with delusional BDD [36,46,47], which has many similarities to ORD [8,18]. (See "Body dysmorphic disorder: Choosing treatment and prognosis".)

Although controlled medication trials are lacking, reviews that summarize case series and case reports of pharmacotherapy, as well as subsequent reports, most strongly support SSRIs or the serotonin reuptake inhibitor tricyclic antidepressant clomipramine (see 'Other treatment options' below). These have been reported to lead to improved symptoms or recovery from symptoms in approximately two-thirds to three-quarters of patients [1,3,8,28,48-51].

●Preference for CBT – We prefer CBT that is tailored to the unique symptoms of ORD as the first-line psychotherapy. In our experience and that of others, effective CBT is similar to that for BDD, and an evidence-based CBT manual for BDD can easily be adapted to treat ORD symptoms [52-54]. (See "Body dysmorphic disorder: Choosing treatment and prognosis", section on 'Cognitive-behavioral therapy'.)

The optimal number and frequency of CBT sessions is not known, but in our experience, many patients need at least six months of weekly hour-long CBT sessions. Some individuals with milder symptoms improve more quickly while others may require a more intensive treatment (more hours per day and/or days per week) and/or longer treatment if response is not seen.

CBT is a structured treatment. The first three or four sessions set the groundwork for therapy by providing psychoeducation, developing an individualized cognitive-behavioral model of the patient's ORD symptoms, and setting treatment goals that reflect the patient's values. Motivational interviewing is used as needed initially and later during treatment to address patient ambivalence about treatment and to enhance adherence to and retention in treatment. (See "Overview of psychotherapies", section on 'Cognitive and behavioral therapies'.)

CBT techniques are adapted for ORD. Core elements of CBT (ie, cognitive restructuring, exposure with behavioral experiments, prevention of rituals/repetitive behaviors, advanced cognitive strategies that focus on maladaptive core beliefs and self-esteem), and other treatment strategies of CBT for BDD that can be modified to treat ORD are discussed elsewhere. (See "Body dysmorphic disorder: Choosing treatment and prognosis", section on 'Cognitive-behavioral therapy'.)

No controlled psychotherapy studies have been done, but review articles that summarize case series and case reports indicate symptom improvement with CBT in a majority of cases [1,3]. Subsequently published case reports similarly indicate that CBT is effective [54-56].

Severe olfactory reference disorder — We prefer treatment with an SSRI combined with CBT that is tailored to ORD for patients with severe ORD (eg, ORD Y-BOCS score of 31 to 48 or a CGI-S scale score of 5 [markedly ill] or higher). This is based on clinical experience and recommendations for similar disorders such as BDD.

Additionally for individuals with prominent passive suicidal ideation, active suicidal ideation, or suicidal behavior, or in those with severe symptoms such as aggressive behavior, prominent delusions, or severe agitation, we begin treatment with both an SSRI and a second-generation antipsychotic in addition to CBT.

We refer all individuals with active suicidal ideation or behavior for inpatient evaluation and treatment. Assessment and management of individuals with suicidal ideation is found elsewhere [57]. (See "Suicidal ideation and behavior in adults" and "Effect of antidepressants on suicide risk in adults".)

The approach of combining an SSRI and a second-generation antipsychotic for ORD has support from a review and subsequently published case series and case reports [1,8,58-62]. (See 'Other treatment options' below.)

SUBSEQUENT TREATMENT

Good response — For individuals with good response to initial pharmacotherapy (ie, goals of treatment are met), we continue the effective medication for at least three to four years.

However, the benefits of second-generation antipsychotics, if used, need to be weighed against safety issues. We are vigilant to monitor for adverse effects, and we consider trying to taper antipsychotic medications after a year or two to avoid these effects.

We suggest that the individual continue to practice learned cognitive-behavioral therapy (CBT) skills after therapy ends to reduce the risk of relapse (see 'Treatment' above). We offer CBT booster sessions for increased support and practice of CBT skills as needed.

For those who have responded to treatment but have had multiple past relapses with medication discontinuation or a severe course of illness (eg, multiple suicide attempts or hospitalizations for olfactory reference disorder [ORD], significant psychosocial dysfunction) our preference is to continue serotonin reuptake inhibitor treatment indefinitely. If an antipsychotic has been used, it can be continued if well tolerated and with appropriate monitoring.

If it has been agreed upon that medication may be discontinued, we suggest a slow taper over six or more months rather than abrupt discontinuation. We monitor for relapse during discontinuation and, if relapse occurs after discontinuation of an effective medication, we suggest resuming the same regimen.

Partial or no response — For patients who obtain insufficient symptom relief from initial management with CBT or pharmacologic management, our first step is to address factors that may be contributing to the limited response. This includes review and confirmation of medication and CBT adherence, and factors such as level of motivation for CBT, length and frequency of therapy, completion of CBT homework assignments, and attendance in therapy.

Combined modality treatment — For patients who have not adequately responded to CBT, our next step is to increase the intensity of CBT (eg, more frequent sessions, longer sessions) and/or add pharmacotherapy (if not already provided). For those who have not adequately responded to medication, CBT can be added (if not already tried) and/or the pharmacotherapy options below can be tried. Combined treatment with medication and CBT is always preferred for severe ORD. (See 'Severe olfactory reference disorder' above.)

Other treatment options — For those who have had inadequate response to pharmacotherapy (or combined treatment, if used) our subsequent pharmacologic management is described below.

●Increase selective serotonin reuptake inhibitor to supratherapeutic dose – Our usual first choice is to gradually increase the dose of the selective serotonin reuptake inhibitor (SSRI) medication to the supratherapeutic range as needed. However, we proceed with caution while monitoring for side effects in all individuals treated with supratherapeutic dose of medication. We monitor for four to six weeks on the maximum dose attained prior to determining response.

We check electrocardiograms for changes in all individuals treated with less than 30 mg of escitalopram or any SSRI in the supratherapeutic range.

In youth (eg, age <14) we usually do not reach the supratherapeutic range or exceed US Food and Drug Administration (FDA) maximum SSRI doses. In adults >65 we do this (if needed) with caution.

The maximum supratherapeutic doses of select SSRIs are found on the table (table 1).

Our preference for increasing to the supratherapeutic range in individuals without initial response to SSRI is based on the efficacy of this approach in treatment of obsessive-compulsive disorder (OCD) and body dysmorphic disorder (BDD) and their similarities with ORD, as well as our clinical experience [44]. (See "Body dysmorphic disorder: Choosing treatment and prognosis", section on 'Patients initially treated with pharmacotherapy' and "Obsessive-compulsive disorder in adults: Treatment overview", section on 'Increasing the SSRI medication to supratherapeutic dose'.)

●Augment with second-generation antipsychotic – Our next step is to augment with a second-generation antipsychotic agent, if not already done (see 'Severe olfactory reference disorder' above). We monitor on the maximum dose of the second-generation antipsychotic that has been attained for at least four to six weeks, if tolerated, prior to deciding on response to treatment or making further changes.

From among second-generation antipsychotics, our preference is treatment with aripiprazole. However, the choice from among second-generation antipsychotics is based on other factors as well. (See "Second-generation and other antipsychotic medications: Pharmacology, administration, and side effects" and "Psychosis in adults: Initial management".)

Our preference is based on the efficacy of this approach in the treatment of OCD and BDD (which have many similarities to ORD), our clinical experience, and case reports supporting the use of antipsychotics when added to an serotonin reuptake inhibitor for ORD [35,36,49,59-64]. (See "Body dysmorphic disorder: Choosing treatment and prognosis", section on 'Patients initially treated with pharmacotherapy' and "Obsessive-compulsive disorder in adults: Treatment overview", section on 'Partial response'.)

●Second SSRI trial – There are no data regarding which SSRI is most effective in the treatment of ORD. Discussion of choosing and dosing of SSRI medication is discussed elsewhere. (See 'Treatment' above and "Selective serotonin reuptake inhibitors: Pharmacology, administration, and side effects" and "Obsessive-compulsive disorder in adults: Treatment overview", section on 'Initiating pharmacotherapy'.)

A different second-generation antipsychotic can be tried as augmentation of the second SSRI, if needed, especially if ORD is severe.

●Switch to clomipramine – We prefer to use the serotonin reuptake inhibitor tricyclic antidepressant clomipramine after several SSRI trials have not adequately improved symptoms.

Clomipramine initiation, dosing, monitoring, and cardiac and other effects of tricyclic antidepressants is discussed elsewhere. (See "Tricyclic and tetracyclic drugs: Pharmacology, administration, and side effects" and "Body dysmorphic disorder: Choosing treatment and prognosis", section on 'Treatment-refractory patients' and "Obsessive-compulsive disorder in adults: Treatment overview", section on 'Subsequent treatment'.)

Limited evidence supports the use of clomipramine in the treatment of ORD. Our use of clomipramine in patients with ORD is consistent with reports of its effectiveness in case series and case reports [3] and with efficacy for BDD and OCD in controlled trials [44,47].

TREATMENTS WITH MINIMAL OR NO SUPPORT — 

Case reports suggest that electroconvulsive therapy is not effective [1,3,21,27,31,32]; however, it can be considered for severely depressed and highly suicidal patients, in combination with serotonergic medication and psychotherapy. There are no data on the efficacy of transcranial magnetic stimulation or deep brain stimulation for olfactory reference disorder (ORD). One report noted partial response of ORD with bilateral partial division of the thalamo-frontal tract [27], but several patients had an unsuccessful outcome with leucotomy [3].

We advise against surgery, nonpsychiatric medical treatment, or dental treatment because these interventions appear to usually be ineffective and leave patients dissatisfied [1,13,19,20]. Because individuals with ORD inaccurately believe that they have a physical problem, they may seek treatment from surgeons, gastroenterologists, proctologists, dentists, otolaryngologists, dermatologists, gynecologists, and other clinicians for other perceived bodily odors [6,8,13,14,19,20,31,32,35,65]. Nearly half to two-thirds of patients seek such treatment for their body odor concerns, consulting an average of two to five different clinicians [8,19]. Despite negative workups, procedures such as tonsillectomies for perceived halitosis, axillary gland excision for perceived sweaty odor, and sphincteroplasty or proctectomy for perceived anal odor/flatulence may be performed [1,8,18,20].

SOCIETY GUIDELINE LINKS — 

Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Obsessive-compulsive disorder and related disorders".)

SUMMARY AND RECOMMENDATIONS

●Olfactory reference disorder – Olfactory reference disorder (ORD) is defined by persistent and distressing or impairing preoccupation with emitting a foul or offensive body odor that is unnoticeable or only slightly noticeable to others. (See 'Introduction' above.)

●Clinical features – Clinical features include a persistent preoccupation with body odor that is time consuming and leads to emotional distress, impairment in functioning, or both. Suicidal ideation may be present. Repetitive behaviors and/or camouflaging behaviors aim to reduce distress by eliminating, preventing, checking, or obtaining reassurance about the perceived smell. Avoidance behaviors are common. (See 'Clinical features' above.)

●Assessment – We undertake a comprehensive psychiatric history and physical examination. We ask about suicidal thoughts and refer for inpatient evaluation if active. We rule out medical or dental conditions that may cause slight body odor or olfactory hallucinations prior to diagnosing ORD. (See 'Assessment and diagnosis' above and 'Suicidality, depression, emotional distress' above.)

●Initial treatment – Options for treatment for ORD include medication management, psychotherapy, or their combination (algorithm 1).

•Mild or moderate ORD – Our initial management of mild or moderate ORD is based primarily on patient preference. However, clinical experience, treatment history, comorbidity, pregnancy and lactation status, and side effects of treatments are also considerations. (See 'Mild or moderate olfactory reference disorder' above.)

For individuals with co-occurring mood, anxiety, and other disorders that may be responsive to pharmacologic management with a selective serotonin reuptake inhibitor (SSRI) or serotonin reuptake inhibitor, we typically prefer treatment with an SSRI to address all of these disorders concurrently.

For those who prefer pharmacologic management, we suggest initial treatment with an SSRI (eg, fluoxetine) rather than other agents (Grade 2C). SSRIs appear to be effective but have not been systematically compared to other treatment approaches (table 1). (See 'Mild or moderate olfactory reference disorder' above.)

For those who prefer psychotherapy, we suggest initial treatment with cognitive-behavioral therapy (CBT) tailored to ORD rather than other types of psychotherapy (Grade 2C). (See 'Mild or moderate olfactory reference disorder' above.)

•Severe ORD – For individuals with severe ORD, we suggest treatment with both pharmacotherapy with an SSRI and CBT that is tailored to ORD rather than either treatment alone (Grade 2C). (See 'Severe olfactory reference disorder' above.)

For patients with prominent passive suicidal ideation, active suicidal ideation, or suicidal behavior, prominent delusions, and/or severe agitation, we suggest the addition of a second-generation antipsychotic (eg, aripiprazole) along with an SSRI (Grade 2C). (See 'Severe olfactory reference disorder' above.)

●Subsequent treatment – For individuals with a good response to SSRI treatment, we continue the effective medication for at least three to four years. (See 'Good response' above.)

For individuals with good response to CBT, we offer CBT booster sessions for ongoing support if needed. (See 'Good response' above.)

For patients with inadequate response to initial management with either modality, our first step is to address factors that may be contributing to the limited response (eg, adherence to treatment, frequency or length of CBT sessions). (See 'Partial or no response' above.)

•For inadequate response to CBT, our next step is to increase the intensity of CBT (eg, more frequent sessions, longer sessions) and/or add pharmacotherapy (if not already provided).

•For those with inadequate response to medication, we add CBT (if not already tried).

●Other treatment options – For ongoing inadequate response to medication we take one of the following steps (see 'Other treatment options' above):

•Increase SSRI to supratherapeutic dose (for SSRIs except citalopram)

•Augment SSRI with a second-generation antipsychotic

Then:

•Second SSRI trial

•SSRI augmentation with a different second-generation antipsychotic, especially if ORD is severe

•Clomipramine trial