More than 6% of US residents over age 40 years expertise “phantom odors” — smells for which there is no such thing as a exterior stimulus, new analysis exhibits.
Investigators studied 7400 adults who participated within the National Heath and Nutrition Examination Survey (NHANES) and located that 1 in 15 members smelled an disagreeable odor when nothing was there to supply it.
The prevalence was larger amongst ladies, youthful people, individuals of decrease socioeconomic standing, these with poorer health, and people with a historical past of head damage or dry mouth signs.
“This study is the first in the US to use nationally representative data to examine the prevalence of and risk factors for phantom odor perception,” lead writer Kathleen Bainbridge, PhD, from the Epidemiology and Biostatistics Program on the National Institute on Deafness and Other Communication Disorders, a part of the National Institutes of Health, instructed Medscape Medical News.
“This study could inform future research aiming to unlock the mysteries of phantom odors,” she mentioned.
The research was published online August 16 in JAMA Otolaryngology-Head & Neck Surgery.
“Miserable” Quality of Life
“The perception of phantom odors is a qualitative olfactory dysfunction whereby affected individuals perceive odors in the absence of an eternal stimulus,” with the odor usually described as “foul,” rotten,” or “chemical,” the authors write.
Few epidemiologic research have addressed this notion, and most proof has been restricted to case stories and small scientific research, they observe.
The organic mechanism of phantom odor notion could come up from aberrant peripheral olfactory neurons that sign notion facilities within the mind or from overactive mind cells that create the notion.
“We knew that phantom odor perception had been observed in medical clinics, but we did not know how common this condition was, nor what types of people are more commonly affected,” Bainbridge commented.
The researchers have been additionally motivated by the “miserable quality of life” that folks with this situation expertise, she mentioned.
To examine, the researchers used information collected between 2011 and 2014 by the NHANES carried out by the National Center for Health Statistics.
Study members (aged ≥ 40 years) have been interviewed about phantom odors and in addition underwent a bodily examination.
Participants have been requested, “Do you sometimes smell an unpleasant, bad, or burning odor when nothing is there?”
The researchers obtained details about sociodemographic traits, together with age, intercourse, and academic attainment, in addition to race/ethnic background.
Individuals labeled as “never” having smoked have been those that reported by no means having smoked 100 cigarettes of their lifetime. Otherwise, smoking standing was outlined as at present smoking day by day, at present smoking some days, or former smoker.
Alcohol use was labeled through the use of a threshold of 12 alcoholic drinks up to now yr.
Participants have been requested to evaluate their basic health standing in addition to reporting on particular bodily situations in the course of the previous yr, together with nasal congestion from allergic reactions, colds or flu lasting greater than 1 month, and chronic dry mouth.
In addition, interview questions assessed lifetime historical past of head damage with ensuing loss of consciousness, damaged nostril or different facial/cranium damage, and greater than two sinus infections.
To assess the potential presence of diminished odor operate, members have been requested to determine eight odors, with diminished odor operate outlined as fewer than six accurately recognized odorants.
Female Sex, Head Injury More Common
The researchers estimated the prevalence of phantom odor notion as 6.5% (n = 534) (95% CI, 5.7% – 7.5%).
Of those that skilled it, solely 11.1% (n = 64) reported discussing a style or odor drawback of any form with a clinician.
Those who reported phantom odors have been much less prone to be youthful than age 70 years than those that didn’t report phantom odors (12.4% [n = 85] vs 19.7% [n = 1698]).
There have been racial/ethnic variations between individuals affected by phantom odors — a larger proportion of non-Hispanic black individuals have been represented amongst those that reported phantom odors.
Conversely, non-Hispanic white people and non-Hispanic Asian people have been represented in larger proportions amongst those that didn’t report phantom odors in contrast with those that did.
The general nationwide pattern was barely greater than half feminine (52.8% [n = 3862]). Of those that reported phantom odors, 68.0% (n = 356) have been ladies.
Men in youthful age teams have been twice as prone to report phantom odors as males aged 70 years or older, though this affiliation was statistically important just for males aged 40 to 49 years
However, in contrast with males aged 70 years or older, ladies on this age group had no larger chance of phantom odor notion; on the opposite hand, ladies within the youthful age teams (40 – 49, 50 – 59, 60 – 69 years) had 5, 6, and 3 instances the percentages of phantom odor notion, respectively.
Phantom odors have been extra widespread in people with solely a highschool training.
Two thirds of these (n = 762) who reported phantom odors have been of decrease revenue (income-to-poverty ration < 3) vs 46.1% of those that didn’t report phantom odors (n = 3749).
Over one quarter (25.3%) of those that reported phantom odors had a historical past of present or former cigarette smoking, in contrast with 17.8% of those that didn’t report phantom odors.
Of individuals labeled as being in honest or poor health, greater than 13% (n = 227) reported phantom odors, in contrast with 5.8% (n = 169) and 4.2% (n = 84) of these in good and excellent/wonderful health, respectively.
People with persistent dry mouth had greater than thrice the prevalence of reporting phantom odors vs those that didn’t (17.4% [n = 204] vs 4.9% [n = 330], respectively).
Of individuals who had sustained head accidents accompanied by loss of consciousness, 10% (n = 112) reported phantom odors, vs 5.7% (n = 422) of these and not using a historical past of head damage.
People who had sustained accidents to their nostril, face, or cranium had no larger prevalence of phantom odor notion, though individuals with diminished odor operate had considerably, however not considerably, decrease prevalence.
“We found some risk factors that may be related to the perception of phantom odor — people are more likely to experienced this condition if they are female and are relatively young,” Bainbridge commented.
Other threat elements included head damage, dry mouth, poor general health, and low socioeconomic standing.
She steered that folks with low socioeconomic standing could “have health conditions that contribute to phantom odors, either directly or because of medications needed to treat their health conditions.”
Commenting on the research for Medscape Medical News, Jeffrey D. Suh, MD, affiliate professor-in-residence, Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA, California, who was not concerned with the research, referred to as it “important, because dysosmia can significantly impair quality of life, and because there is very little consensus in the diagnosis, management, and treatment of patients that suffer from this condition.”
Greater understanding “of the incidence of phantosmias and risk factors” ought to allow clinicians “to better be able to diagnose and treat their treatment,” mentioned Suh, who’s the coauthor of an accompanying editorial.
Study coauthor Donald Leopold, MD, scientific professor, Department of Surgery, University of Vermont Medical Center, Burlington, steered reassuring sufferers that experiencing phantom odors is normally a brief situation and resolves spontaneously in 1 yr.
Treatment approaches would possibly embrace blocking nasal airflow with saline, particularly when utilized with the pinnacle inverted, and contemplating a trial with antidepressants or anticonvulsants, notably gabapentin.
The National Institute on Deafness and Other Communication Disorders supplied funding help for National Health and Nutrition Examination Survey chemosensory information assortment by way of interagency agreements with theNational Center for Health Statistics of the Centers for Disease Control and Prevention and the University of Connecticut. Support for the statistical evaluation was supplied by Social & Scientific Systems Inc. Bainbridge, Leopold, and the opposite research authors, in addition to Suh and the editorial coauthor, have disclosed no related monetary relationships.