Fear of Body Odour

The outcome figures are the reason this entry leads with them. Seventy-four per cent of people with the condition avoid social situations. Forty-seven per cent avoid work, academic or other important activities. Forty per cent have been housebound for at least a week because of it. Thirty-one point six per cent have experienced psychiatric hospitalisation. Reports give suicidal ideation in between forty-three and sixty-eight per cent, at least one suicide attempt in thirty-two per cent, and death by suicide in 5.6 per cent.

Which odours people with olfactory reference syndrome report

Halitosis is the most common form: seventy-five per cent complain of bad breath, alone or with other odours, and sweat is next at sixty per cent. Other reported sources are the anus, the genitals, the skin generally, the groin, armpits and feet, and the source may change over time.

The character of the odour divides in two. Some report bodily substances: faeces, flatus, urine, sweat, vomit, semen, vaginal secretions. Others report something unnatural or chemical, and the list is unexpectedly precise: ammonia, detergent, rotten onions, burnt rags, candles, rubbish, burning fish, medicines, old cheese. The odour is typically reported as continuously present.

Whether the person can smell the odour

The distribution here is the most informative thing in the entry. In one review, the person was unreservedly convinced they could detect the odour themselves in twenty-two per cent of cases, detected it occasionally or intermittently in nineteen per cent, and could not detect it at all in fifty-nine per cent.

Where the odour is perceived, that perception is usually considered phantosmia, an olfactory hallucination, and which way the causation runs is open: the hallucination may follow from the delusional belief, or the belief may follow from the hallucination.

Where it is not perceived, the belief is sustained by interpreting other people's behaviour, or by concluding that a disorder of smell prevents self-detection.

How ordinary gestures are read as odour reactions

Ideas of reference are present in seventy-four per cent of cases, and the catalogue of misread behaviour is worth reproducing because it is so ordinary: coughing, sneezing, turning the head, opening a window, facial expressions, sniffing, touching the nose, scratching the head, gestures, moving away, avoiding the person, whistling.

They are more pronounced in stressful social settings, public transport, a crowded lift, a workplace, a classroom. Where other people nearby are talking among themselves, the person is commonly convinced the conversation is about their odour. Even a dog barking can be read as referential.

How people try to hide the odour

Ninety-five per cent engage in at least one excessive hygiene, grooming or related repetitive practice, and the odour is still reported to offend.

• repeated showering, excessive tooth brushing and tongue scraping
• smelling oneself to check, and over-frequent bathroom use
• masking, with deodorants, perfume, mouthwash, mint, chewing gum, scented candles and soap
• changing underwear several times a day, washing clothes constantly, wearing several layers
• wrapping feet in plastic, and buying garments marketed as odour-reducing
• special diets and supplements intended to reduce flatulence odour
• sitting at a distance from other people, minimising movement so as not to spread the odour, keeping the mouth closed, talking with a hand in front of it

And seeking reassurance, which fails in a specific way: the negative answer is usually interpreted as politeness rather than as truth.

Excessive washing has been reported to cause eczema, which produces a real skin condition out of the response to an unreal one.

Whether olfactory reference syndrome is a delusional disorder

Some distinguish a delusional form, with complete conviction that the odour is real, from a non-delusional form in which the person retains some insight and can recognise that the odour may not exist and that their concern is excessive.

In one review, fifty-seven per cent held their beliefs with complete conviction and could not be reassured, and forty-three per cent held them with less than complete conviction and could to varying degrees consider the possibility that the odour was not there.

Because the core belief is sometimes not of delusional intensity, treating the condition as a form of delusional disorder, as the DSM appears to, is argued to be inappropriate. Others hold that reported cases present a spectrum of insight rather than two types.

What triggers olfactory reference syndrome

Unknown, with significant negative experiences thought to trigger it, of two kinds. In one review, eighty-five per cent of reported cases had traumatic smell-related experiences and seventeen per cent had stress factors unrelated to smell.

The smell-related experiences usually involve family, friends, colleagues or peers commenting on an odour, producing embarrassment and shame. The examples given are specific and several are cruel. The material adds an important qualification: some of those reported experiences may not have been real, and may instead have been an early symptom, meaning a referential thought recalled as an event.

Neuroimaging exists in single cases rather than in series. One case showed hypoperfusion of the frontotemporal lobe on SPECT. In another, functional imaging during exposure to emotionally loaded words showed more activation than in a matched control, described as abnormal but less pronounced than would be seen in a psychotic disorder.

Depression, often severe, may follow the condition or precede it. Cluster C personality disorders, predominantly avoidant, may be present, along with bipolar disorder, schizophrenia, hypochondriasis, substance misuse and obsessive-compulsive disorder.