A short Chemical Sensitivity Scale for assessment of airway sensory hyperreactivity

Validity and reliability of the Swedish version of the Leicester Cough Questionnaire in unexplained chronic cough

BACKGROUND

Cough is considered chronic when it lasts for >8 weeks. When no medical explanation can be found it is often called unexplained chronic cough (UCC), which may affect health-related quality of life (HRQOL). This study aimed to assesses the validity and reliability of the Swedish version of the Leicester Cough Questionnaire (LCQ-S) in patients with UCC.

METHODS

Seventy-six consecutively selected patients with UCC replied to: a local questionnaire; the LCQ-S; a Visual Analog Scale (VAS) for cough; the Swedish version of the Hull Airway Reflux Questionnaire (HARQ-S); and the Chemical Sensitivity Scale for Sensory Hyperreactivity (CSS-SHR). To evaluate the reproducibility of the LCQ-S, the VAS and LCQ-S were answered again after two to four weeks.

RESULTS

Seventy-four patients (17 men) answered the questionnaires at baseline. Concurrent validity for LCQ-S was regarded as moderate with the VAS for cough and HARQ-S. Internal consistency using Cronbach's alpha was high for the LCQ-S total score (0.92) and satisfactory for the LCQ-S domains (0.78-0.83). Reliability and reproducibility were analysed in 57 patients (14 men). Intra-class correlation for the LCQ-S total score and domains showed strong reliability (≥0.92), without any significant differences over time. The standard error of measurement and the smallest real difference were 1.26 and 3.49, respectively. The Bland-Altman plot showed no systematic change in the mean values.

CONCLUSIONS

The LCQ-S has good validity and reliability and can be used in clinical settings to evaluate HRQOL in Swedish-speaking adult patients with UCC.

Evaluation and management of chronic cough in adults

Background: Chronic cough (CC), a cough that lasts > 8 weeks, has an overall prevalence of 5-11% in adults, peaking between 60 and 80 years of age. Of the 15% of patients who remain undiagnosed or refractory to treatment, two thirds are women. Objective: The objective was to present an updated evidence-based algorithmic approach for evaluating and managing CC, with emphasis on treatment modalities for refractory CC. Methods: A literature search was conducted of medical literature data bases for guidelines, position papers, systematic reviews, and clinical trials from January 2022 to June 2023, on the evaluation and management of CC. Results: The initial assessment should be limited to a detailed history, physical examination, chest radiograph, spirometry, exhaled nitric oxide, blood eosinophil count, and measurement of cough severity and quality of life by using validated instruments. The top diagnoses to consider are asthma, chronic obstructive pulmonary disease, nonasthmatic eosinophilic bronchitis, gastroesophageal reflux disease, and upper airway cough syndrome. Additional studies are only obtained when red flags are present or the patient fails to respond after avoidance of high-risk factors, e.g., smoking and angiotensin-converting enzyme inhibitors, and 4-6 weeks of empiric treatment for the most likely respiratory and gastrointestinal diseases. When diagnostic tests and/or specific directed treatments fail to control CC, low-dose morphine (preferred), gabapentin, pregabalin, and/or cough control therapy are recommended. Non-narcotic purinergic 2×3 (P2×3) receptor antagonists, gafapixant and campilixant, are currently being studied for CC. Conclusion: For the evaluation and management of patients with CC, clinicians should use an algorithmic approach and identify "red flags," reduce high-risk factors, and use empiric treatment for the five top diagnoses before extensive diagnostic testing. Current treatment for refractory cough is limited to symptomatic management.

Modern health worries and annoyance from environmental factors are largely unrelated to smoking, alcohol consumption, and physical activity

OBJECTIVE

Modern health worries, as well as environmental annoyance from chemical agents, noise, and electromagnetic exposure are associated with symptom reporting and marked affective-behavioural changes. As promotion and protection of health is a primary characteristic of these conditions, it can be expected that they will be related to less risk behaviour (smoking and alcohol consumption) and more health behaviour (physical activity), both cross-sectionally and longitudinally.

METHODS

Hypotheses were tested in a sample of 2336 individuals participating in T1 and T2 data collection (3 years apart) of the Västerbotten Environmental Health Study, Sweden. Health-related behaviours were assessed using single self-report questions. Smoking was measured on a binary (yes-or-no) scale; frequency of alcohol consumption and physical activity was measured on a 5-point and a 4-point scale, respectively.

RESULTS

Modern health worries showed no cross-sectional association with the three behaviours, whereas annoyance was typically inversely, very weakly, related to smoking and alcohol consumption. Physical activity was significantly positively associated only with chemical annoyance. None of the variables significantly predicted change of behaviours at T2 after controlling for the respective T1 value and demographic variables.

CONCLUSIONS

Individuals with high levels of modern health worries and annoyance from various environmental agents are not clearly characterized by a healthier lifestyle. Perhaps they focus on the alleviation of their existing symptoms; alternatively, somatic symptom distress decreases their cognitive-affective resources necessary for a long-term life style change.

Multiple Chemical Sensitivity: It's time to catch up to the science

Multiple chemical sensitivity (MCS) is a complex medical condition associated with low dose chemical exposures. MCS is characterized by diverse features and common comorbidities, including fibromyalgia, cough hypersensitivity, asthma, and migraine, and stress/anxiety, with which the syndrome shares numerous neurobiological processes and altered functioning within diverse brain regions. Predictive factors linked to MCS comprise genetic influences, gene-environment interactions, oxidative stress, systemic inflammation, cell dysfunction, and psychosocial influences. The development of MCS may be attributed to the sensitization of transient receptor potential (TRP) receptors, notably TRPV1 and TRPA1. Capsaicin inhalation challenge studies demonstrated that TRPV1 sensitization is manifested in MCS, and functional brain imaging studies revealed that TRPV1 and TRPA1 agonists promote brain-region specific neuronal variations. Unfortunately, MCS has often been inappropriately viewed as stemming exclusively from psychological disturbances, which has fostered patients being stigmatized and ostracized, and often being denied accommodation for their disability. Evidence-based education is essential to provide appropriate support and advocacy. Greater recognition of receptor-mediated biological mechanisms should be incorporated in laws, and regulation of environmental exposures.

Impact of comorbidity on symptomatology in various types of environmental intolerance in a general Swedish and Finnish adult population

Comorbidity with various health conditions is common in environmental intolerances (EIs), which restricts understanding for what symptoms that are associated with the intolerance per se. The present objectives were to study (i) prevalence of a broad range of specific symptoms in chemical, building-related, electromagnetic field- (EMF) related, and sound EI, irrespective of comorbidity, (ii) prevalence of symptoms in body systems in exclusive EIs, and (iii) increased risk of symptoms in body systems in exclusive EIs that cannot be referred to functional somatic syndromes, inflammatory diseases or mental disorders. Cross-sectional data (n = 4941) were used from two combined population-based surveys, the Västerbotten (Sweden) and Österbotten (Finland) Environmental Health Studies. Categorization of EI cases and controls were based on self-reports. Symptoms were assessed with the Environmental Hypersensitivity Symptom Inventory, and these were converted to 27 symptoms of the International Classification of Primary Care, 2nd edition, in eight chapters of body systems. The results showed, with few exceptions, that all assessed specific symptoms were significantly more prevalent in all four EIs than in referents. Although a large overlap between EIs, characteristic body system symptoms were eye and respiratory symptoms in chemical and building-related intolerance, skin symptoms in EMF-related intolerance, and general and unspecified, digestive, eye, cardiovascular, neurological, and psychological symptoms in sound intolerance. After controlling for various comorbidities, all studied body system symptoms were positively associated with chemical intolerance, fewer with sound intolerance, only one with building-related intolerance, and none with EMF-related EI. In conclusion, a broad range of symptoms are reported in all four EIs implying common mechanisms, but symptoms of certain body systems are more likely to be reported in a certain EI that cannot be explained by comorbidity.

Development and Psychometric Validation of the Taste And Smell Tool for Evaluation (TASTE) Questionnaire

Importance

The human senses of taste and smell are essential in everyday life. However, as clinical testing of the senses and patient-reported sensory problems are often diverging, additional validated questionnaires are essential for the evaluation of chemosensory impairments.

Objective

To develop an instrument with all relevant domains concerning chemosensory dysfunction and quality of life using modern psychometrics.

Design, Setting, and Participants

The study was designed as a questionnaire study for developing a new instrument. The study started in 2019 and was completed in 2022. Patients with chemosensory dysfunction were recruited from a specialized smell and taste clinic at an ear, nose, and throat department in Denmark. Healthy participants with no history of chemosensory dysfunction were recruited through social media.

Main Outcomes and Measures

Eight domains were included (distorted chemosensation, emotional, food and meals, social, hygiene, danger, work, and relationship), and 35 items were generated based on review of the existing literature and interviews with patients and experts. Participants were tested with the Major Depression Inventory, 36-Item Short Form Health Survey, Taste Sprays, and Sniffin' Sticks for chemosensory function. Descriptive statistics were calculated for all items. Reliability, internal consistency, and validity were investigated, and a Rasch model was fitted. Healthy controls (n = 39) filled out the questionnaire for comparison of known-groups validity. Confirmatory factor analysis was performed. Finally, item reduction was performed, resulting in a final version with 21 items in 8 domains.

Results

The study included responses from 316 patients, 183 women (58%) and 133 men (42%), with a mean (SD) age of 57 (15.1) years. Rasch model fit was acceptable with P > .05 for all items. An 8-dimensional confirmatory factor analysis model showed a better fit than a bifactor confirmatory factor analysis model. Cronbach α ranged from 0.65 to 0.86. Criterion validity with the Sniffin' Sticks, Taste Sprays, Major Depression Inventory, and the 36-Item Short Form Health Survey was satisfactory. The test-retest reliability was good in all domains, ranging from 0.55 to 0.86. All domains were discriminative, except the social and work domains.

Conclusions and Relevance

In this survey study, the instrument was validated with 8 domains related to chemosensory dysfunction and quality of life. All items had good internal consistency, test-retest reliability, interitem correlations, item-total correlations, and Rasch model fit. The questionnaire appears suitable for use in clinical and research settings.

Physiological Health and Physical Performance in Multiple Chemical Sensitivity-Described in the General Population

Multiple chemical sensitivity (MCS) is a multifactorial somatic disorder characterized by physical reactions triggered by even extremely low levels of different airborne chemicals. In most individuals with MCS, these reactions have substantial negative impact on social, occupational, and everyday life often including limited or no engagement in physical activities. The aim of this study was to explore associations between MCS and objective measurements of anthropometry, cardiorespiratory health, and physical performance. From the Danish population-based cohort DanFunD counting 9656 participants aged 18–76 years, 1.95% (n = 188) were categorized as MCS individuals (MCS All). Of those 188, 109 participants were subcategorized as having MCS without functional somatic disorders (FSD) (MCS with no comorbid FSD). The remaining study population without any FSD were regarded controls. We used adjusted multiple linear regression analyses to evaluate associations between MCS and anthropometry, cardiorespiratory fitness, and physical performance. Compared with the general population, MCS All had less optimal body composition, increased risk of obesity, impaired cardiorespiratory fitness, and physical performance which was not seen in MCS with no comorbid FSD. MCS individuals may be inhibited to maintain an active lifestyle which can increase risk of obesity and consequently have negatively impact on general health, which may not be the case among MCS with no comorbid FSD.

Odor perception and symptoms during acrolein exposure in individuals with and without building-related symptoms

Building-related symptoms (BRS) is a significant work-related and public health problem, characterized by non-specific symptoms occurring in a particular building. The cause of BRS is unknown, but certain reactive compounds are suggested risk factors. The aim of this controlled exposure study was to investigate whether BRS cases report more odor annoyance and symptoms and show altered autonomous nervous system (ANS) response during exposure to the reactive aldehyde, acrolein in comparison with referents. Individuals with BRS (n = 18) and referents (n = 14) took part in two exposure sessions (80 min). One session contained heptane alone, and the other heptane and acrolein. Perceived odor annoyance; eye, nose, and throat symptoms; and ANS response were measured continuously. BRS cases did not experience more odor annoyance; eye, nose, and throat symptoms; or altered ANS response in comparison with referents during the exposures. Supplementary analyses revealed that BRS cases that also reported chemical intolerance perceived more symptoms than referents during acrolein exposure. Acrolein exposure at a concentration below previously reported sensory irritation detection thresholds is perceived as more irritating by a subgroup of BRS individuals compared with referents. The results of this study indicate that a subset of individuals with building related symptoms (BRS) has a lowered sensory irritation threshold towards acrolein exposure. Future guidelines on chemical exposures to acrolein should take time and individual sensitivity into account.

Psychological models of development of idiopathic environmental intolerances: Evidence from longitudinal population-based data

The origin of idiopathic environmental intolerances (IEIs) is an open question. According to the psychological approaches, various top-down factors play a dominant role in the development of IEIs. The general psychopathology model assumes a propensity towards mental ill-health (negative affectivity) increases the probability of developing IEIs. The attribution model emphasizes the importance of mistaken attribution of experienced somatic symptoms; thus, more symptoms should lead to more IEIs. Finally, the nocebo model highlights the role of expectations in the development of IEIs. In this case, worries about the harmful effects of environmental factors are assumed to evoke IEIs. We estimated cross-lagged panel models with latent variables based on longitudinal data obtained at two time points (six years apart) from a large near-representative community sample to test the hypothesized associations. Indicators of chemical intolerance, electromagnetic hypersensitivity, and sound sensitivity fit well under a common latent factor of IEIs. This factor, in turn, showed considerable temporal stability. However, whereas a positive association was found between IEIs and increased somatic symptoms and modern health worries six years later, the changes therein could not be predicted as hypothesized by the three psychological models. We discuss the implications of these results, as well as methodological aspects in the measurement and prediction of change in IEIs.

Multiple Chemical Sensitivity

Multiple Chemical Sensitivity (MCS), a condition also known as Chemical Sensitivity (CS), Chemical Intolerance (CI), Idiopathic Environmental Illness (IEI) and Toxicant Induced Loss of Tolerance (TILT), is an acquired multifactorial syndrome characterized by a recurrent set of debilitating symptoms. The symptoms of this controversial disorder are reported to be induced by environmental chemicals at doses far below those usually harmful to most persons. They involve a large spectrum of organ systems and typically disappear when the environmental chemicals are removed. However, no clear link has emerged among self-reported MCS symptoms and widely accepted objective measures of physiological dysfunction, and no clear dose-response relationship between exposure and symptom reactions has been observed. In addition, the underlying etiology and pathogenic processes of the disorder remain unknown and disputed, although biologic and psychologic hypotheses abound. It is currently debated whether MCS should be considered a clinical entity at all. Nevertheless, in the last few decades MCS has received considerable scientific and governmental attention in light of the many persons reporting this illness. In this review, we provide a general overview of the history, definition, demographics, prevalence, and etiologic challenges in defining and understanding MCS.

Multiple chemical sensitivity described in the Danish general population: Cohort characteristics and the importance of screening for functional somatic syndrome comorbidity-The DanFunD study

Background

Multiple chemical sensitivity (MCS) is characterized by widespread symptoms attributed to exposure to airborne chemicals. MCS is categorized as a functional somatic syndrome (FSS), and MCS cases often meet the criteria for other types of FSS, e.g. fibromyalgia. The primary aim was to characterize MCS regarding symptom triggers, symptoms, lifestyle and describe demographics, socioeconomics and lifestyle factors associated with MCS. A secondary aim was to examine the implication of FSS comorbidity.

Methods

Data were derived from a random sample of the Danish adult population enrolled in the Danish Study of Functional Disorders (DanFunD; n = 9,656). Questionnaire data comprised information used to delimit MCS and four additional types of FSS, as well as data on demographics, socioeconomics and lifestyle. MCS cases (n = 188) was stratified into subgroups; MCS only (n = 109) and MCS with comorbid FSS (n = 73). Information regarding FSS comorbidities were missing for six MCS cases. MCS subgroups and controls without FSS comorbidities (n = 7,791) were compared by means of logistic regression analyses, adjusted for age and sex.

Results

MCS was associated with female sex, not being in occupation and low social status, but not with age or education. MCS cases reported normal dietary intake and smoking habits and lower alcohol consumption. Additional associations were found between MCS and low rate of cohabitation, sedentarism, daily physically limitations, and poor quality of sleep. However, subgroup analysis revealed that these findings were primarily associated with MCS with comorbid FSS.

Conclusions

MCS was associated with lower socioeconomic status, physically inactivity and poor quality of sleep. Subgroup analysis revealed that several associations was explained by FSS comorbidity, i.e. MCS cases with no comorbid FSS showed normal rate of cohabitation and did not report physical limitations or difficulties sleeping. Overall, our findings emphasise the importance of screening MCS cases for FSS comorbidity both in epidemiological and clinical settings.

Chemical Intolerance Is Associated With Altered Response Bias, not Greater Sensory Sensitivity

Chemical intolerance is a surprisingly prevalent condition or affliction characterized by adverse reactions to low levels of chemical, often odorous stimulation. Sufferers often assume that their plight is due to an uncommon sensory acuteness, yet studies repeatedly fail to reveal altered detection thresholds. Here, we investigated whether self-reported chemical intolerance is associated with altered sensory sensitivity or response bias. The sensory acuity (sensitivity; A) and sensory decision rule (criterion; B) to n-butanol was assessed using the method of constant stimuli in 82 participants with different degrees of chemical intolerance (low to high). Higher self-reported chemical intolerance was associated with a lower criterion, but not with sensitivity.

Multisensory environmental sensitivity in patients with chronic tinnitus

OBJECTIVE

The study aimed at investigating the sensitivity to noise and chemosensory environmental stressors as well as the relation to perceived stress, depression and anxiety in subjects with chronic tinnitus as compared to subjects without tinnitus.

METHODS

We included 75 subjects with chronic tinnitus and 75 age and sex-matched subjects without tinnitus. Standardized questionnaires assessing the level of distress and impairment of quality of life caused by tinnitus, perceived level of stress, anxiety and depression, environmental noise and chemosensory sensitivity were used. A subgroup of 27 subjects with chronic tinnitus and 20 age-matched subjects without tinnitus underwent testing of olfactory function with the Sniffin' Sticks test and testing of intranasal trigeminal function using CO2 thresholds.

RESULTS

Our data confirmed the increased environmental noise sensitivity (NSS) in patients with tinnitus. Furthermore, we observed an increased environmental chemosensory sensitivity (CSS), but no difference in measured chemosensory function. Subjects with tinnitus showed also significant higher levels of perceived stress, anxiety and depression and those symptoms partially correlated to CSS and NSS. Predictors of both NSS and CSS results were the presence / absence of tinnitus and high anxiety levels while neither stress nor depression were found as predicting variables.

CONCLUSIONS

The results suggest that chronic tinnitus is related to a multisensory environmental hypersensitivity. Anxiety seems to be a predictor of this environmental vulnerability.

Development and evaluation of a questionnaire instrument for chemical intolerance, based on the International Classification of Functioning, Disability and Health

PURPOSE

The purpose was to develop a questionnaire instrument to measure difficulties in activities and participation, and impact of environmental factors in chemical intolerance, based on the International Classification of Functioning, Disability and Health, and to assess its validity and reliability.

METHOD

Development in three steps: (1) choosing items of relevance for chemical intolerance with an expert group, (2) conducting interviews with persons with chemical intolerance, using sampling to redundancy, (3) conducting a survey with 112 respondents at a first assessment and 91 at a second assessment for test-retest.

RESULTS

The final version of the instrument consists of 57 items divided in three parts, which showed good internal consistency in each part, Cronbach alpha: 0.73-0.87. It had good content validity, readability and face validity. Test-retest showed good to very good (≥0.61) Kappa agreement for 37 items, and moderate (0.41-0.60) for 17 items. Three items had poor or fair (<0.41) Kappa agreement.

CONCLUSION

The instrument was found to be valid and reliable. It can be used as a clinical tool to help persons with chemical intolerance to receive the best suited help and support for each individual, identify key points in rehabilitation, measure rehabilitation outcome and establish priority for treatment.IMPLICATIONS FOR REHABILITATIONThe questionnaire instrument based on the International Classification of Functioning, Disability and Health which was developed and evaluated in this study, can be used to measure difficulties in activities and participation, and impact of environmental factors in chemical intolerance.Persons with chemical intolerance report lack of support from healthcare and society. Using this questionnaire instrument can help forming the best suited help and support for each individual based on his/her preconditions.This questionnaire instrument can be used to identify key points in rehabilitation and measure rehabilitation outcome.

Comorbidity of Airway Inflammatory Diseases in Chemical and Building-Related Intolerance

OBJECTIVES

This study investigated comorbidity in chemical intolerance (CI) and building- related intolerance (BRI) with (i) chronic sinusitis, chronic obstructive pulmonary disease, allergic and nonallergic asthma and allergic rhinitis, and (ii) airway inflammatory symptoms.

METHODS

Data from two population-based questionnaire surveys, the Västerbotten and Österbotten Environmental Health Studies, were used. The participants were categorized as CI or BRI and referents, and binary logistic regression analysis was applied.

RESULTS

Prevalence rates for the case groups were 7.2% to 40.0% for diseases and 24.3% to 68.9% for symptoms, whereas adjusted odds ratios (ORs) were 3.4 to 26.1 for diseases and 3.3 to 17.0 for symptoms, all being significantly higher than unity. Prevalence rates and ORs were in general higher in BRI than in CI.

CONCLUSION

Inflammatory airway diseases and symptoms are associated with CI and BRI, which encourages further research regarding underlying mechanisms and treatments.

National Prevalence and Effects of Multiple Chemical Sensitivities

OBJECTIVE

The aim of this study was to assess the prevalence of multiple chemical sensitivities (MCS), its co-occurrence with asthma and fragrance sensitivity, and effects from exposure to fragranced consumer products.

METHODS

A nationally representative cross-sectional population-based sample of adult Americans (n = 1137) was surveyed in June 2016.

RESULTS

Among the population, 12.8% report medically diagnosed MCS and 25.9% report chemical sensitivity. Of those with MCS, 86.2% experience health problems, such as migraine headaches, when exposed to fragranced consumer products; 71.0% are asthmatic; 70.3% cannot access places that use fragranced products such as air fresheners; and 60.7% lost workdays or a job in the past year due to fragranced products in the workplace.

CONCLUSION

Prevalence of diagnosed MCS has increased over 300%, and self-reported chemical sensitivity over 200%, in the past decade. Reducing exposure to fragranced products could help reduce adverse health and societal effects.

Multiple Chemical Sensitivity: Review of the State of the Art in Epidemiology, Diagnosis, and Future Perspectives

OBJECTIVE

Systematic bibliography analysis of about the last 17 years on multiple chemical sensitivity (MCS) was carried out in order to detect new diagnostic and epidemiological evidence. The MCS is a complex syndrome that manifests as a result of exposure to a low level of various common contaminants. The etiology, diagnosis, and treatment are still debated among researchers.

METHOD

Querying PubMed, Web of Science, Scopus, Cochrane library, both using some specific MESH terms combined with MESH subheadings and through free search, even by Google.

RESULTS

The studies were analyzed by verifying 1) the typology of study design; 2) criteria for case definition; 3) presence of attendances in the emergency departments and hospital admissions, and 4) analysis of the risk factors.

OUTLOOK

With this review, we give some general considerations and hypothesis for possible future research.

Factors affecting self-reported chemical intolerance: A five-year follow-up study in Japan

OBJECTIVE

Chemical intolerance (CI) has become a strong public health concern in industrialized countries. The Japanese Chemical Intolerance (JCI) study was conducted in January 2012 with a cohort of 7245 adults from population-based sampling as the baseline. The aim of the present study was to investigate the factors involved in the improvement and development of CI from the five-year follow-up study.

METHODS

From the 7245 cohort, 735 persons with CI (case) were identified, and 1750 controls without CI were randomly selected to match gender and age for case and control groups. Self-reported questionnaires were administered to the subjects of the two groups to obtain information on status of CI; medical history; medical, lifestyle, or physical interventions; changes in living situation or occupation; and psychosomatic states.

RESULTS

A total of 909 individuals responded during the follow-up period. After five years, improvement in CI was observed in 67.7% of the case group. Status of CI was reported in 6.7% of the control group. Multiple logistic regression analyses revealed that baseline atopic dermatitis and negative psychosomatic states including irritability, fatigue, anxiety, depressed mood, and somatic symptoms were significantly associated with development of CI in controls. Appropriate physical activity and maintaining a regular lifestyle including diet or sleep during the last three years of the follow-up period were significant factors for improvement of CI in the case group.

CONCLUSIONS

Ensuring appropriate physical activity and regular lifestyle rather than improving physical environment lead to improvement of CI. Stable psychosomatic state is essential for preventing CI.

Background factors of chemical intolerance and parent-child relationships

Background

Chemical intolerance is a widespread public health problem characterized by symptoms that reportedly result from low-level exposure to chemicals. Although several studies have reported factors related to chemical intolerance in adults, the impact of family members has not been reported. In the present study, we investigated the background factors related to chemical intolerance in family members and parent–child relationships.

Methods

We distributed a self-reported questionnaire to 4325 mothers who were invited to visit the Kishiwada Health Center in Kishiwada City, Osaka, between January 2006 and December 2007 for the regular health checkup of their three-and-a-half-year-old children.

Results

The prevalence of chemical intolerance in the 3-year-old children was almost one eighteenth of that reported by their mothers. Multiple logistic regression analyses revealed that cold sensitivity [odds ratio (OR), 1.89; 95% confidence interval (CI), 1.04–3.44], past bronchial asthma (OR, 2.84; 95% CI, 1.46–5.53), and any past allergies (OR, 2.21; 95% CI, 1.36–3.60) were significantly associated with chemical intolerance in the mother. The presence of indoor cat during childhood (OR, 1.99; 95% CI, 1.08–3.69) was significantly associated with chemical intolerance in the mother; however, the association was weak compared with cold sensitivity and past asthma and allergies. The current chemical intolerance of the mother was significantly associated with allergic rhinitis (OR, 2.32; 95% CI, 1.19–4.53), bronchial asthma (OR, 3.66; 95% CI, 2.00–6.69), and chronic bronchitis (OR, 3.69; 95% CI, 1.04–13.03) in her 3-year-old child.

Conclusions

The results suggest that inherent physical constitution and childhood housing environment are associated with a risk of acquiring chemical intolerance. Children of mothers with chemical intolerance have a possible risk of respiratory hypersensitivity or inflammation. Further investigation is recommended to determine the inherent physical constitution and background environmental factors associated with the risk of acquiring chemical intolerance. The impact of having mothers with chemical intolerance on the health of children also requires further study.

Electronic supplementary material

The online version of this article (10.1186/s12199-018-0743-y) contains supplementary material, which is available to authorized users.

Background Odors Modulate N170 ERP Component and Perception of Emotional Facial Stimuli

Successful social interaction relies on the accurate decoding of other peoples’ emotional signals, and their contextual integration. However, little is known about how contextual odors may lead to modulation of cortical processing in response to facial expressions. We investigated how unpleasant and pleasant contextual background odors affected emotion perception and cortical event-related potential (ERP) responses to pictures of faces expressing happy, neutral and disgusted facial expressions. Faces were, regardless of expression, rated more positively in the pleasant odor condition and more negatively in the unpleasant odor condition. Faces were overall rated as more emotionally arousing in the presence of an odor, irrespective of its valence. Contextual odors also interacted with facial expressions, such that happy faces were rated as especially non-arousing in the unpleasant odor condition. The early, face-sensitive N170 ERP component also displayed an interaction effect. Here, disgusted faces were affected by the odor context such that the N170 revealed a relatively larger negativity in the context of a pleasant odor compared with an unpleasant odor. There were no odor effects on the responses to faces in other measured ERP components (P1, VPP, P2, and LPP). These results suggest that odors bias socioemotional perception early stages of the visual processing stream. However, effects may vary across emotional expressions and measurements.

Long-Term Follow-Up in Patients With Airway Chemical Intolerance

OBJECTIVE

A 5-year follow-up study showed that a group of patients with airway symptoms from chemicals and scents had lasting symptoms, together with enduring increased capsaicin cough sensitivity. The aim was to follow up the same patients after another 5 years.

METHODS

All previously participants were invited for an additional follow-up. They visited the clinic twice; at one opportunity, they undertook a capsaicin inhalation provocation, and at the other, a methacholine provocation, and answered various questionnaires.

RESULTS

Sixteen patients attende the study after a median of 8 years. They reported unchanged symptoms from chemicals and scents; the capsaicin cough sensitivity was still increased, and the repeatability for the capsaicin inhalation was good.

CONCLUSIONS

Airway symptoms induced by chemicals and scents constitute a chronic disease, with unchanged trigger factors, persistent symptoms, and unchanged, long-lasting sensory hyperreactivity.All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.This study was supported by grants from the Herman Krefting Foundation Against Asthma/Allergy, the Swedish Heart and Lung Foundation, and the Swedish Cancer and Allergy Fund.

Symptom-trigger factors other than allergens in asthma and allergy

Several environmental exposures of particular relevance for indoor air quality, such as exposure to odorants, may be associated with asthma and allergy. The aim of this study was to investigate attribution of symptoms and behavioral disruptions to various chemical and physical environmental sources in persons with self-reported asthma and allergy. Data from a population-based study, the Västerbotten Environmental Health Study, were used to compare persons with asthma, allergic rhinitis, allergic dermatitis, multiple diagnoses of asthma/allergy and no asthma or allergy. Persons with asthma and multiple diagnoses reported odorous/pungent and building-related environmental factors to trigger symptoms to a larger extent than did the reference group, mainly due to perfume and odors from flowers. They also reported behavioral disruptions and affective reactions to odorous/pungent environments. These findings increase the understanding of the role of odorants in symptom development and thereby the prevention of health problems in asthma and allergy in indoor air.

Sleep and sleepiness in environmental intolerances: a population-based study

BACKGROUND

About one fourth of the general population report environmental intolerance (EI) to odorous/pungent chemicals, certain buildings, electromagnetic fields (EMFs), and/or sounds. EI sufferers show various clinical features, of which sleep disturbance is one. Sleep disturbance is common also in the general population, but it is not known whether the disturbance is more prominent in EI sufferers than in individuals who do not experience EI. Therefore, EI was compared on various sleep aspects with referents without EI.

METHODS

A population-based sample of 3406 individuals, aged 18-79 years, was recruited from Northern Sweden. Sleep quality, non-restorative sleep, daytime sleepiness, obstructive breathing, and nocturnal insomnia were assessed with the Karolinska Sleep Questionnaire. Single questions assessed time slept, amount of hours of needed sleep, and extent of enough time slept.

RESULTS

All four EI groups, compared to the referents, reported significantly poorer sleep quality, more non-restorative sleep, more daytime sleepiness, more obstructive breathing and higher prevalence of nocturnal insomnia than the referents. Nocturnal insomnia was an important factor for EI groups attributing their most prevalent symptoms to chemicals and sounds, irrespective of distress and certain syndromes. None of the EI groups differed significantly from the referents on time slept, but reported needing more sleep time (the EMF-intolerance group showing only a tendency), and all four groups reported to perceive enough sleep to a significantly lesser extent.

CONCLUSION

Sleep disturbance and daytime sleepiness are more common in individuals reporting EI compared to normal referents. Moreover, nocturnal insomnia is an important symptom in its own right in various types of EI. This evokes the question of whether or not sleep therapy may attenuate the severity of the EI.

Intolerance to environmental chemicals and sounds in irritable bowel syndrome: Explained by central sensitization?

This study tested the hypotheses of irritable bowel syndrome showing (1) comorbidity with chemical and sound intolerance, other types of functionally somatic syndromes, and psychiatric disorders and (2) stronger than normal affective reactions to and behavioral disruptions from odorous/pungent chemicals and sounds in daily life. These hypotheses were tested by means of data from a large-scale population-based questionnaire study. The results showed comorbidity in irritable bowel syndrome with chemical and sound intolerance, fibromyalgia, migraine, post-traumatic stress disorder, generalized anxiety disorder, panic syndrome, and depression as well as strong reactions/disruptions from odorous/pungent chemicals and sounds in irritable bowel syndrome.

Physical Therapy Treatment of Impaired Chest Mobility in Patients with Airway Sensory Hyperreactivity

BACKGROUND AND PURPOSE

In sensory hyperreactivity (SHR), patients have symptoms from the airways and the chest induced by environmental irritants like scenting products and cigarette smoke. They are characterized by increased cough reaction to inhaled capsaicin compared with healthy controls. Lung function tests are normal, and asthma medications have no or little effect. In a recent published article, patients with SHR were found to have impaired chest mobility and increased pain sensitivity. The purpose of this study was to evaluate if a physiotherapeutic intervention can increase chest mobility in SHR, influence these patients' symptoms and reduce capsaicin cough sensitivity.

METHODS

Forty-one SHR patients were initially randomized in to groups, one for training and one for symptom registration in this controlled training study. It consisted of a daily training programme containing simple movements to increase the flexibility of the chest, a breathing exercise and a relaxation session as well as symptom registration. Chest expansion was measured with a measuring tape and thoracic and abdominal movement with light sensors. Pain sensitivity was assessed using pressure algometry and a standardized capsaicin inhalation threshold provocation-evaluated cough sensitivity.

RESULTS

Twenty seven patients were left for analyses after 12 weeks and 26 patients after 24 weeks. Chest mobility and upper thoracic respiratory movements improved (p < 0.01), feeling of chest pressure and the capsaicin cough sensitivity decreased (p < 0.01). The patients also showed of significantly lowered pain pressure thresholds measured with algometry, compared with healthy controls (p < 0.001).

CONCLUSION

Improvement of chest mobility after physiotherapeutic intervention indicates that these patients may have acquired a dysfunctional breathing pattern. The regular use of a training programme and structural breathing instructions can be used to improve chest mobility, chest symptoms and capsaicin cough sensitivity in patients with SHR and signs of dysfunctional breathing. Copyright © 2016 John Wiley & Sons, Ltd.

Eucapnic voluntary hyperpnoea and exercise-induced vocal cord dysfunction

INTRODUCTION

Exercise-induced bronchoconstriction (EIB) is a common condition in endurance athletes. Exercise-induced vocal cord dysfunction (EIVCD) is a frequent confounder of EIB. The diagnosis of EIVCD may be challenging and can be missed as the problem is often intermittent and may only occur during intense exercise. Eucapnic voluntary hyperventilation (EVH) is the best test to detect EIB. This pilot study aimed to assess if EVH could be helpful in the diagnosis of EIVCD associated or not to EIB in athletes.

METHODS

A nasolaryngoscopy was performed during a 6 min EVH test, in 13 female athletes suspected to have VCD, aged 21±7 years. Image analysis was conducted by two Ear Nose and Throat surgeons in random order.

RESULTS

During the EVH, three athletes showed incomplete paradoxical vocal cords movement, without inspiratory stridor. However, 12 athletes showed marked supraglottic movement without inspiratory stridor. In two athletes, this supraglottic movement was severe, one showing a marked collapse of the epiglottis with an almost complete obstruction of the larynx by the arytenoid cartilage mucosa. In 3 of the 12 athletes with supraglottic movement, severe vibration of the mucosa covering the arytenoid cartilages was also observed.

CONCLUSIONS

EVH challenge in athletes can provide information on various types of glottic and supraglottic obstruction in reproducing laryngeal movements during hyperventilation. Our findings make us suggest that exercise induced upper airway obstructions should be named: Exercise-induced laryngeal obstruction (EILO). Then, EILO should be divided in three categories: supraglottic, glottic (EIVCD) and mixed (glottic and supraglottic) obstruction.

Assessment of cerebral blood flow in patients with multiple chemical sensitivity using near-infrared spectroscopy--recovery after olfactory stimulation: a case-control study

OBJECTIVES

Multiple chemical sensitivity (MCS) is a chronic acquired disorder characterized by non-specific symptoms in multiple organ systems associated with exposure to odorous chemicals. We previously observed significant activations in the prefrontal cortex (PFC) during olfactory stimulation using several different odorants in patients with MCS by near-infrared spectroscopy (NIRS) imaging. We also observed that the patients with MCS did not adequately distinguish non-odorant in the late stage of the repeated olfactory stimulation test. The sensory recovery of the olfactory system in the patients with MCS may process odors differently from healthy subjects after olfactory stimulation.

METHODS

We examined the recovery process of regional cerebral blood flow (rCBF) after olfactory stimulation in patients with MCS. NIRS imaging was performed in 6 patients with MCS and in 6 controls. The olfactory stimulation test was continuously repeated 10 times. The study also included a subjective assessment of the physical and psychological status and of the perception of irritating and hedonic odors.

RESULTS

After olfactory stimulation, significant activations were observed in the PFC of patients with MCS on both the right and left sides compared with controls. The activations were specifically strong in the orbitofrontal cortex (OFC). Compared with controls, autonomic perception and feelings identification were poorer in patients with MCS. OFC is associated with stimuli response and the representation of preferences.

CONCLUSIONS

These results suggest that a past strong exposure to hazardous chemicals activates the PFC during olfactory stimuli in patients with MCS, and a strong activation in the OFC remains after the stimuli.

Prevalence and Characteristics of Chemical Intolerance: A Japanese Population-Based Study

Population-based cross-sectional study was performed to estimate the prevalence of chemical intolerance and to examine the characteristics of the sample. A Web-based survey was conducted that included 7,245 adults in Japan. The criteria for chemical intolerance proposed by Skovbjerg yielded a prevalence of 7.5% that was approximately consistent with that reported from a Danish population-based survey. Female gender, older age, and renovation in the house during the past 7 years were positively associated with chemical intolerance. Improvements in the condition were observed with daily ventilation habits. Medical history of atopic dermatitis, allergic rhinitis, food allergy, multiple chemical sensitivity, and depression were associated with chemical intolerance. Fatigue, depressed mood, and somatic symptoms were also positively correlated with chemical intolerance. Better elucidation of the causes, comorbidities, concomitants, and consequences of chemical intolerance has the potential to provide effective solutions for its prevention and treatment.

Changes in cerebral blood flow during olfactory stimulation in patients with multiple chemical sensitivity: a multi-channel near-infrared spectroscopic study

Multiple chemical sensitivity (MCS) is characterized by somatic distress upon exposure to odors. Patients with MCS process odors differently from controls. This odor-processing may be associated with activation in the prefrontal area connecting to the anterior cingulate cortex, which has been suggested as an area of odorant-related activation in MCS patients. In this study, activation was defined as a significant increase in regional cerebral blood flow (rCBF) because of odorant stimulation. Using the well-designed card-type olfactory test kit, changes in rCBF in the prefrontal cortex (PFC) were investigated after olfactory stimulation with several different odorants. Near-infrared spectroscopic (NIRS) imaging was performed in 12 MCS patients and 11 controls. The olfactory stimulation test was continuously repeated 10 times. The study also included subjective assessment of physical and psychological status and the perception of irritating and hedonic odors. Significant changes in rCBF were observed in the PFC of MCS patients on both the right and left sides, as distinct from the center of the PFC, compared with controls. MCS patients adequately distinguished the non-odorant in 10 odor repetitions during the early stage of the olfactory stimulation test, but not in the late stage. In comparison to controls, autonomic perception and negative affectivity were poorer in MCS patients. These results suggest that prefrontal information processing associated with odor-processing neuronal circuits and memory and cognition processes from past experience of chemical exposure play significant roles in the pathology of this disorder.

A study of two generic health-related quality of life questionnaires--Nottingham Health Profile and Short-Form 36 Health Survey--and of coping in patients with sensory hyperreactivity

BACKGROUND

Sensory hyperreactivity (SHR) is one explanation for airway symptoms induced by chemicals and scents. Little is known about health-related quality of life (HRQOL) and coping, in this group of patients. A study was done in patients with SHR to (1) compare the Nottingham Health Profile (NHP) and the Short-Form 36 Health Survey (SF-36) in regard to their suitability, validity, reliability, and acceptability; (2) evaluate how the patients cope with the illness; (3) assess whether there are differences between women and men with respect to HRQOL and coping; and (4) assess whether there are differences between patients and normative data with respect to HRQOL and coping.

METHODS

A total of 115 patients (91 women) with SHR were asked to answer five questionnaires: a study-specific questionnaire, the Chemical Sensitivity Scale for Sensory Hyperreactivity (CSS-SHR), the NHP, the SF-36, and the Jalowiec Coping Scale-60.

RESULTS

Eighty-three patients (72%; 70 women) completed all questionnaires. The SF-36 scores were less skewed and more homogeneously distributed and showed fewer floor and ceiling effects than the NHP scores. The SF-36 was also discriminated better between patients with high and low CSS-SHR scores. The reliability standard for both questionnaires was satisfactory. There were no gender differences in HRQOL. Patients with SHR had significantly lower HRQOL scores than the normative data in comparable domains of the NHP and the SF-36: emotional reactions/mental health, energy/vitality, physical mobility/functioning, and pain/bodily pain. In social isolation/functioning, the results were different; the NHP scores were similar to the normative data and the SF-36 scores were lower. The most commonly used coping styles were optimistic, self-reliant, and confrontational. Women used optimistic coping more than men. Compared with the normative group, patients with SHR used confrontational and optimistic coping more and emotive coping less.

CONCLUSIONS

The current findings showed that both the NHP and the SF-36 were reliable instruments; but the results suggest that the SF-36 is a more sensitive instrument than the NHP for elucidating HRQOL in patients with SHR. Patients with SHR experienced a poor HRQOL and they followed the Western tradition of preferring problem-focused coping strategies to palliative and emotive strategies.

Metric properties and normative data for brief noise and electromagnetic field sensitivity scales

Aims: Lack of brief questionnaire instruments for quantifying affective reactions to and behavioral disruptions attributed to sounds and electromagnetic fields (EMFs) motivated the present development and metric evaluation of such instruments, called the 11-item Noise Sensitivity Scale (NSS-11) and the 11-item Electromagnetic Field Sensitivity Scale (EMFSS-11). Another objective was to establish normative data for these instruments. Method: Data from 3406 individuals who took part in the Västerbotten Environmental Health Study was used. The participants constitute a random sample of inhabitants in the county of Västerbotten in Sweden, aged 18 to 79 years, stratified for age and gender. The participants responded to the NSS-11 and EMFSS-11 and to additional questions for evaluation of concurrent validity. Results: The results show satisfying reliability (Cronbach α = 0.71–0.85, varying with age group and gender), concurrent validity, and unidimensionality of the NSS-11 and EMFSS-11, and that the scales generate scores with approximately normal distributions, irrespective of age group and gender. Mean scores, standard deviations, and confidence intervals constitute normative data. Conclusions: The favorable metric properties of the NSS-11 and EMFSS-11 in combination with their fast usage suggest that they are particularly useful for assessment in epidemiological studies, and have the advantage of available normative data.

Normative data for the chemical sensitivity scale for sensory hyperreactivity: the Västerbotten environmental health study

OBJECTIVES

The chemical sensitivity scale for sensory hyperreactivity (CSS-SHR) is used to quantify affective reactions to and behavioral disruptions by odorous/pungent substances in the environment and has documented good metric properties. However, normative data have not been available. The main objective of the present study was therefore to establish normative data for reference by means of a large-scale population-based study.

MATERIALS AND METHODS

From a random sample of 8,520 reachable inhabitants in the county of Västerbotten in Sweden, aged 18-79 years, stratified for age and gender, 3,406 individuals agreed to participate.

RESULTS

The results show fairly high internal consistency (Cronbach's α = 0.78-0.83) of the CSS-SHR and that it generates scores with approximately normal distributions (skewness: 0.045-0.454; kurtosis: -0.314 to 0.230), irrespective of age group and gender. Mean scores, standard deviations, confidence intervals, and proportions of individuals who met the diagnostic cutoff score for the CSS-SHR were obtained for reference of normality.

CONCLUSIONS

CSS-SHR can be recommended for quantification of affective reactions to and behavioral disruptions by odorous/pungent environmental substances, and with the advantage of comparing scores with normality.

Clinical characteristics of chronic rhinitis patients with high vs low irritant trigger burdens

BACKGROUND

Patients with chronic allergic rhinitis (AR) and nonallergic rhinitis (NAR) often experience irritant-induced symptoms. The clinical relevance of the magnitude of their symptoms in response to these nonspecific stimuli remains unclear.

OBJECTIVE

To determine the internal consistency and validity of an irritant index questionnaire (IIQ) and whether reclassification of physician-diagnosed rhinitis subtypes based on IIQ scores results in rhinitis subtypes with different clinical characteristics.

METHODS

Patients 18 to 65 years old with physician-diagnosed AR (n = 404), mixed rhinitis (MR; n = 129), or NAR (n = 123) completed an IIQ that rated rhinitis symptom severity in response to 21 nonallergic irritant triggers on a 1- to 10-point scale. Multistage sex-specific statistical analyses were performed using IIQ responses to reclassify physician-diagnosed AR, MR, and NAR into categories with high and low irritant burdens.

RESULTS

The IIQ demonstrated good internal consistency and cross-validation. After reclassification, 48% and 52% of patients with physician-diagnosed AR patients (n = 533) were categorized as having low-burden AR and high-burden AR, respectively, whereas 64% and 36% of NAR (n = 123) patients were categorized as having low-burden NAR and high-burden NAR, respectively. Reclassified high-burden AR and high-burden NAR patients were more likely to have a physician diagnosis of asthma and a greater number of self-reported rhinitis symptoms and perennial symptoms with seasonal exacerbations than reclassified low-burden AR and low-burden NAR patients, respectively (P < .01).

CONCLUSION

The IIQ resulted in significant reclassification of physician-diagnosed rhinitis patients into different diagnostic categories with unique clinical characteristics. Further studies are necessary to confirm the IIQ's utility as a tool for characterizing rhinitis patients in clinical practice and research.

Diagnosis of asthma - a new approach

Current definition of asthma involves four cornerstones: inflammation, hyperresponsiveness, bronchoconstriction, and symptoms. In research, the symptoms have had the slightest attention. According to international guidelines, the asthma symptoms are episodic breathlessness, wheeze, cough, tightness of the chest, and shortness of breath. As there are several symptoms, a primary question is how they are related to bronchoconstriction, the main clinical feature of asthma. Symptoms and lung function tests are regularly used for the evaluation of clinical health status and effect of treatment. However, there is no or poor correlation between these two variables, which means that they represent different mechanisms. Reduced lung function, such as a low FEV(1) , represents bronchial constriction, what do the symptoms represent? Some symptoms such as breathlessness and shortness of breath seem not to be evidence-based asthma symptoms. Focusing on bronchial obstruction is important in view of the potential risk of asthma attacks, but nonobstructive symptoms occur frequently and may also cause severe discomfort and poor quality of life. Interpreting all symptoms as signs of bronchoconstriction (asthma) may lead to misinterpretation when assessing health status and effect of treatment. Although a 'soft' variable, the strength of symptoms is that they are representing various mechanisms. The physiological preconditions for control and defense of respiration must be considered in the diagnostic process, regardless of inflammation, allergy, psychology, or other etiological factors. Based on studies on dyspnea in cardiopulmonary diseases, including asthma and asthma-like disorders, there seems to be a continuous spectrum of symptoms and mechanisms integrated in a single asthma syndrome.

Respiratory movement and pain thresholds in airway environmental sensitivity, asthma and COPD

INTRODUCTION

Patients with "sensory hyperreactivity" (SHR) have airway environmental sensitivity, chronic cough and dyspnoea. Cough, chest discomfort and sense of difficulties getting air are some of the symptoms these patients seek medical attendance for. The patients have increased cough sensitivity to inhaled capsaicin, mediated by ion channel receptors on sensory nerves also known to react to pain stimuli. Whether a link exists between capsaicin airway sensitivity and pain sensitivity has not yet been evaluated. The aim was to investigate chest mobility, respiratory movement and pain sensitivity in SHR patients compared with patients with asthma, chronic obstructive pulmonary disease (COPD) and alleged healthy control subjects.

METHODS

Thirty-five patients diagnosed with SHR, 19 with COPD, 32 with asthma and 28 control subjects were included. Chest expansion was measured with a measuring tape and thoracic and abdominal movement with light sensors. Pain sensitivity was assessed using a pressure algometer.

RESULTS

Groups differed significantly in lung function, respiratory rate and pain sensitivity but also in chest expansion and abdominal breathing movement. In comparison with the control and asthma groups but not the COPD patients, SHR patients had an increased respiratory rate and reduced abdominal movement during deep breathing. All patient groups showed lower pain thresholds than the controls.

CONCLUSION

Patients with SHR have evident signs of dysfunctional breathing and appeared to be most similar to the COPD group except for lung function. Lower pain thresholds among the patients indicate a general up-regulation of the sensory nerve system.

Evaluation of the quick environmental exposure and sensitivity inventory in a Danish population

Objectives. To evaluate a Danish translation of the Quick Environmental Exposure and Sensitivity Inventory (QEESI). Methods. The study included two groups: one comprised a random sample of 2000 individuals drawn from the Danish Civil Registration System; the other comprised 315 patients with chemical intolerance. Results. The evaluation suggested good reliability for the four QEESI scales in terms of internal consistency and coefficients between test and retest scores. The discriminatory validity was the largest for the Chemical (inhalant) Intolerance and Life Impact Scales. Using combined cut-off scores for these two scales provided a sensitivity of 92.1 and a specificity of 91.8 and yielded a prevalence of 8.2% in the population group. Conclusions. The Danish translation of the QEESI showed overall good reliability and validity. We recommend the use of the combined Chemical (inhalant) Intolerance and Life Impact Scales in future studies.

A randomised cross-over cohort study of exposure to emissions from a road tunnel ventilation stack

BACKGROUND AND OBJECTIVE

Road tunnels are increasingly important components of urban infrastructure. However, knowledge of their health impact on surrounding communities is limited. Our objective was to estimate the short-term respiratory health effects of exposure to emissions from a road tunnel ventilation stack.

METHODS

We conducted a randomised cross-over cohort study in 36 volunteers who underwent three exposure scenarios in 2006 before the road tunnel opened, and in 2007 (n=27) and 2008 (n=20) after the tunnel opened. Exposure downwind of the stack was compared to upwind of the stack and to a distant heavily trafficked location adjacent to a main road. Spirometry, exhaled nitric oxide (eNO) and symptom scores were measured repeatedly during each 2 h exposure session.

RESULTS

Downwind locations were associated with increased reports of 'dry nose' (score difference 0.36; 95% CI 0.09 to 0.63) compared with the control location (2006 vs 2007/2008), but not with impaired lung function, increased airway inflammation or other symptoms. The heavily trafficked location was associated with significantly increased eNO (ratio=1.09; 95% CI 1.04 to 1.14), eye (score difference 0.05; 95% CI 0.01 to 0.10) and chest (score difference 0.21; 95% CI 0.09 to 0.33) symptoms compared to the stack locations.

CONCLUSIONS

There was no consistent evidence of adverse respiratory effects from short-term exposures downwind of the tunnel ventilation stack, except for dry nose symptoms. However, the findings of increased airway inflammation and symptoms in subjects after only 2 h exposure at the heavily trafficked location, are suggestive of detrimental effects of short-term exposures to traffic-related air pollution.

Sensitivity to environmental irritants and quality of life in COPD

It is a common clinical experience that patients with chronic obstructive pulmonary disease (COPD) complain of airway symptoms provoked by environmental irritants like chemicals and scents, although few studies can confirm such connections. The aim was to study the prevalence of airway symptoms induced by chemicals and scents in a group of patients with newly diagnosed CPOD and to analyze any relation to illness severity and quality of life. Eighty-one patients with COPD were recruited to the study. By mail they were asked to answer three questionnaires regarding symptoms, quality of life, and social and emotional influence of airway symptoms induced by environmental irritants. A majority (62%) of the COPD patients claimed to be hyperreactive to chemicals and scents. As a group they scored higher on a questionnaire measuring social and emotional influences of such environmental irritants compared to healthy control subjects. Further, high scores were more common among patients with a very severe form of COPD and among patients with regular use of β(2)-stimulants. High scores were also associated with significantly more airway symptoms and, in some aspects, with impaired quality of life. In conclusion, the results of this study show that airway symptoms induced by environmental irritants are common in patients with COPD and that this increased airway sensitivity follows the impairment of lung capacity. The mechanisms behind this remain unclear.

Symptoms induced by environmental irritants and health-related quality of life in patients with chronic cough - A cross-sectional study

BACKGROUND

Chronic cough is a common condition, but some patients have no evident medical explanation for their symptoms. A group of patients has been identified, characterized by upper and lower airway symptoms triggered by chemicals and scents, and heightened cough sensitivity to inhaled capsaicin. Chronic cough is usually a prominent symptom in these patients, and it has been suggested that they suffer from sensory hyperreactivity.Our main aim was to analyse, in a group of patients with chronic cough, the presence of symptoms induced by environmental factors such as chemicals, scents, and cold air, and to measure the social and emotional influences of these symptoms in relation to quality of life. A second aim was to pilot-test a Swedish translation of a cough-specific questionnaire.

METHODS

A total of 119 patients with chronic cough were asked to answer three different questionnaires: a local symptom questionnaire, the Chemical Sensitivity Scale for Sensory Hyperreactivity (CSS-SHR), and the Nottingham Health Profile (NHP). In addition, a Swedish version of the Hull Airway Reflux Questionnaire (HARQ) was developed and answered by a subgroup of patients and healthy controls.

RESULTS

Sixty-two patients (52%) with mean cough duration of 10.6 years answered the local symptom questionnaire, the CSS-SHR, and the NHP. Of these, 39 (63%) claimed to have cough and other symptoms induced by chemicals and scents. Compared to population-based findings, the patients scored higher on the CSS-SHR, and the CSS-SHR score was significantly higher among chemical-sensitive individuals (p < 0.001). The NHP showed that the patients had a significantly reduced quality of life, which was most pronounced among chemical-sensitive individuals. The 31 patients who answered the HARQ had significantly higher scores (p < 0.0001) than 59 healthy controls.

CONCLUSIONS

Among patients with chronic cough, a majority claimed that environmental factors induced coughing. Both the CSS-SHR and the HARQ score systems seem to be valuable instruments in the mapping of cough patients, supporting the novel paradigm of a cough hypersensitivity syndrome. Our results emphasize that cough is a substantial burden to the patient, influencing daily living and quality of life.

Sensitivity to environmental irritants and capsaicin cough reaction in patients with a positive methacholine provocation test before and after treatment with inhaled corticosteroids

BACKGROUND

Increasing evidence points to a potential role for members of the transient receptor potential family of cation channels on several features of asthmatic disease. The cough sensitivity to inhaled capsaicin is known to reflect the reactivity of these airway sensory nerves.

OBJECTIVE

The aim was to study, among patients having a positive methacholine provocation and diagnosed with asthma, capsaicin cough sensitivity, sensitivity to methacholine, and levels of exhaled nitric oxide before and after treatment with inhaled steroids, and further, to measure the self-reported impact from environmental irritants.

METHODS

Eighteen steroid-naïve patients with a positive methacholine test underwent capsaicin inhalation provocation on two occasions, before and after regular use of inhaled steroids over at least 3 months. Comparisons were made to 21 healthy controls. Sensitivity to methacholine and levels of exhaled nitric oxide were measured before and after the treatment. The participants also answered a validated questionnaire regarding environmental irritants.

RESULTS

The patients displayed higher capsaicin cough sensitivity than the controls before the treatment period, but not afterward. Before treatment, capsaicin cough answer correlated significantly with levels of exhaled nitric oxide, but not with methacholine sensitivity. After treatment with inhaled corticosteroids, the capsaicin cough sensitivity and the inflammatory parameters were normalized. In comparison to the control group, the patients reported more affective reactions to and behavioral disruptions induced by environmental irritants.

CONCLUSIONS

In steroid-naïve patients with a positive methacholine test, there is a link between that part of the airway inflammation that is reflected by exhaled nitric oxide and that followed by an augmented reactivity of capsaicin-sensitive sensory nerves. This association disappears after steroid treatment.

The airway sensory hyperreactivity syndrome

After exclusion of diverse pulmonary illnesses, the remaining explanations for chronic cough include medication with angiotensin-converting enzyme (ACE) inhibitor, gastroesophageal reflux disease (GERD), and post-nasal drip. Different clinics report shifting frequencies for both the causes of chronic cough and the success of treatment. However, after all evaluations, differential diagnosis still leaves a group of patients with unexplained cough. This unexplained cough is also known as chronic idiopathic cough (CIC), though there are widely varying opinions as to its existence. Among patients previously diagnosed with CIC, a subgroup has been identified with both upper and lower airway symptoms, including cough induced by odours and chemicals, and with increased cough sensitivity to inhaled capsaicin, which is known to stimulate the airway sensory nerves. A suggested explanation for this condition is a hyperreactivity of the sensory nerves of the entire airways, and hence the condition is known as sensory hyperreactivity (SHR). SHR affects more than 6% of the adult population in Sweden. It is a longstanding condition, and is clearly associated with significant social and psychological impacts.

Experiences of problems in individuals with hypersensitivity to odours and chemicals

AIM

The purpose of the study was to describe how individuals with hypersensitivity to odours and chemicals handle their problems.

BACKGROUND

One group of patients we often encounter consists of those with upper and lower respiratory problems who also have a pronounced sensitivity to odours and chemicals. Earlier studies have shown that these symptoms can be related to sensory hyperreactivity (SHR). This hyperreactivity is characterised by respiratory tract symptoms triggered by odours and chemicals, along with high sensitivity to inhaled capsaicin and a positive score on the chemical sensitivity scale for SHR. However, there is still a lack of studies in which SHR sufferers describe their situations in their own words.

DESIGN

The study was conducted using a qualitative approach.

METHODS

Eight individuals with confirmed SHR were selected from a population-based epidemiological study and interviewed. A qualitative content analysis was performed on the data.

RESULTS

Four themes emerged from the data analysis: Limitations in one's life situation, Lack of understanding from others, Concern that the symptoms will develop into a serious disease and Disparagement of one's own personal experience. The results show how individuals manage their daily lives with the help of various strategies, how they relate to other people, how they cope with their concerns and the fact that they sometimes choose to disparage their own experience of their problems.

CONCLUSION

The results indicate that people with SHR experience limitations in their life situations. These limitations consist of the adjustments they make to avoid triggering factors.

RELEVANCE TO CLINICAL PRACTICE

To improve care, nurses need to know how people experience SHR and how they cope with their hypersensitivity to odours and chemicals.

Relationship of airway sensory hyperreactivity to asthma and psychiatric morbidity

BACKGROUND

Patients with airway symptoms induced by chemicals and odors are common in allergy clinics, but the problems cannot be explained by allergic or asthmatic reactions. Previous studies have shown that these patients often have increased sensitivity to inhaled capsaicin, which is known to reflect sensory reactivity; a diagnosis of airway sensory hyperreactivity (SHR) has been suggested for this condition.

OBJECTIVES

To examine the relationship between asthma and SHR and to investigate whether patients with SHR show signs of increased psychiatric morbidity.

METHODS

This study included 724 patients who were attending an allergy center because of suspected allergy or asthma. All the patients completed a quantitative questionnaire on self-reported affective reactions and behavioral disruptions caused by odorous/pungent substances. A standardized capsaicin inhalation test was performed and a questionnaire to assess psychiatric morbidity was administered in patients with pronounced chemical sensitivity to identify those with SHR.

RESULTS

The prevalence of SHR was approximately 6% in asthmatic patients in the allergy center population, which is in accordance with the prevalence in a general population. There was no significant indication that SHR was related to either depression or anxiety.

CONCLUSION

There is no strong relationship between SHR and either asthma or psychiatric morbidity.

Repressive coping and alexithymia in idiopathic environmental intolerance

OBJECTIVE

To examine if the non-expression of negative emotions (i.e., repressive coping) and differences in the ability to process and regulate emotions (i.e., alexithymia) is associated with idiopathic environmental intolerance (IEI).

METHODS

The study included participants who had previously participated in a general population-based study and reported symptoms of environmental intolerance (n = 787) and patients with IEI (n = 237). The participants completed questionnaires assessing IEI, namely, a measure of repressive coping combining scores on the Marlowe-Crowne Social Desirability Scale (MCSDS) and the Taylor Manifest Anxiety Scale (TMAS), the Toronto Alexithymia Scale (TAS-20), and a negative affectivity scale (NAS). Multiple, hierarchical linear regression analyses were conducted using IEI variables as the dependent variables.

RESULTS

The TMAS and MCSDS scores were independently associated with the IEI variables, but there was no evidence of a role of the repressive coping construct. While the total alexithymia score was unrelated to IEI, the TAS-20 subscale of difficulties identifying feelings (DIF) was independently associated with symptoms attributed to IEI. Negative affectivity was a strong independent predictor of the IEI variables and a mediator of the association between DIF and IEI.

CONCLUSION

Our results provide no evidence for a role of repressive coping in IEI, and our hypothesis of an association with alexithymia was only partly supported. In contrast, strong associations between IEI and negative emotional reactions, defensiveness and difficulties identifying feelings were found, suggesting a need for exploring the influence of these emotional reactions in IEI.