Asthma and odors: The role of risk perception in asthma exacerbation

Abstract

Objective Fragrances and strong odors have been characterized as putative triggers that may exacerbate asthma symptoms and many asthmatics readily avoid odors and fragranced products. However, the mechanism by which exposure to pure, non-irritating odorants can elicit an adverse reaction in asthmatic patients is still unclear and may involve both physiological and psychological processes. The aim of this study was to investigate how beliefs about an odors relationship to asthmatic symptoms could affect the physiological and psychological ‘ responses of asthmatics. Methods Asthmatics classified as ‘moderate-persistent’, according to NIH criteria, were exposed for 15 mi to a fragrance which was described either as eliciting or alleviating asthma symptoms. During exposure, participants were asked to rate odor intensity, perceived irritation and subjective annoyance while physiological parameters such as electrocardiogram, respiratory rate, and end tidal carbon dioxide (etCO2) were recorded. Before, immediately after, and at 2 and 24 h post-exposure, participants were required to subjectively assess their asthma symptom status using a standardized questionnaire. We also measured asthma status at each of those time points using objective parameters of broncho-constriction (spirometry) and measures of airway inflammation (exhaled nitric oxide, FeNO). Results Predictably, manipulations of perceived risk altered both the quality ratings of the fragrance as well as the reported levels of asthma symptoms. Perceived risk also modulated the inflammatory airway response. Conclusions Expectations elicited by smelling a perceived harmful odor may affect airway physiology and impact asthma exacerbations.

Parental worry about indoor air quality and student symptom reporting in primary schools with or without indoor air quality problems

“…In a series of experimental studies, it has been shown that participants who received negative information about an odor stimulus reported more respiratory or other symptoms than participants who received positive information about it. [31][32][33] Also, healthy volunteers informed about the expected physiological effect of the exposure reported more symptoms in comparison with uninformed volunteers who reported no symptoms after exposure. 34 In addition to cognitive processes, the perception and interpretation of somatic information can be influenced by psychological states.…”

A systematic review of factors that contribute to nocebo effects.

“…Symptoms are common in everyday life (Petrie, Faasse, Critchon, & Grey, 2014), and although often harmless and short-lived, when people are subjected to a new exposure, symptoms that were present before or occur coincidentally are available to be mistakenly attributed to it (Petrie et al, 2005; Petrie, Moss-4 Morris, Grey, & Shaw, 2004). Therefore factors such as high baseline symptoms or high selfawareness may serve as risk factors for nocebo effects resulting from this mechanism.Negative expectations can also mediate nocebo effects (Hahn, 1997), and may in turn arise through explicit suggestions about the effects of an exposure (Jaen & Dalton, 2014; Myers, Cairns, & Singer, 1987), or predisposing factors such as pessimism (Geers, Helfer, Kosbab, Weiland, & Landry, 2005). These negative expectations can make the individual more likely to attend to new or current sensations, and attribute them to the exposure (Barsky et al, 2002).…”

Health hazard evaluation report: evaluation of indoor environmental quality and health concerns in a commercial office building near a helipad.

“…Evidence also exists that odors caused by air pollutants can have psychological and central nervous system effects such as anxiety and panic attacks [Beach et al 1997;Jaén and Dalton 2014;Shusterman 2002]. In hospital settings, helicopter exhaust fumes can enter building ventilation systems at levels above odor thresholds [Petersen et al 1990].…”