Work-related asthma from cleaning agents versus other agents.

BACKGROUND: Cleaning agents have been commonly implicated as causative or triggering factors in work-related asthma (WRA), mainly from epidemiologic studies. Relatively few clinical series have been reported. AIMS: We aimed to compare socio-demographic and clinical features among tertiary clinic patients with WRA exposed to cleaning and non-cleaning products. METHODS: Analyses were conducted on a patient database containing 208 patients with probable WRA referred to the asthma and airway centre at a tertiary centre hospital in Canada from 2000 to 2014. Chi-squared and independent samples t-tests were used to analyse categorical and continuous data, respectively. RESULTS: Twenty-two (11%) WRA cases were attributed to a variety of cleaning product exposures, 12 were diagnosed as occupational asthma (OA) and 10 as work-exacerbated asthma (WEA) (10% of all OA and 11% of all WEA). There were multiple exposures and the responsible agent(s) could seldom be clearly identified. Most frequent categories of exposure were surfactants, alcohols, disinfectants and acids. Compared to WRA with other exposures, those with cleaning agent exposures had a significantly larger proportion of females (82 versus 35%, P < 0.001), included a higher percentage of workers in healthcare (41 versus 4%, P < 0.001), and submitted more workers' compensation claims (86 versus 64%, P = 0.05). Other characteristics were comparable. CONCLUSIONS: In a tertiary referral clinic, patients with WRA from cleaning agent exposure had clinical characteristics that were similar to those with WRA from other causes. Most frequent exposures were surfactants, alcohols, disinfectants and acids.

Health survey of employees regularly using 3D printers.

Background: 3D printers emit potentially hazardous ultrafine particles and volatile organic compounds. Workers using 3D printing technologies may be at risk of respiratory illness from occupational exposure. Aims: To assess whether 3D printing is associated with health effects in occupational users. Methods: This was a preliminary survey. Workers in 17 companies using 3D printing, including commercial prototyping businesses, educational institutions and public libraries, in the Greater Toronto Area, Canada, were asked to complete survey questionnaires concerning demographic, occupational and health information. Associations between self-reported health history variables and occupational characteristics were examined by chi-square and Fisher's exact tests. Results: Among 46 surveyed workers, 27 (59% of participants) reported having respiratory symptoms at least once per week in the past year. Working more than 40 h per week with 3D printers was significantly associated with having been given a respiratory-related diagnosis (asthma or allergic rhinitis) (P < 0.05). We observed a wide variation in occupational hygiene practices in the 17 printing workplaces that we surveyed. Conclusions: Our finding of frequently reported respiratory symptoms suggests a need for additional studies on exposed workers in this field.

Case report of asthma associated with 3D printing.

BACKGROUND: Three-dimensional (3D) printing is being increasingly used in manufacturing and by small business entrepreneurs and home hobbyists. Exposure to airborne emissions during 3D printing raises the issue of whether there may be adverse health effects associated with these emissions. AIMS: We present a case of a worker who developed asthma while using 3D printers, which illustrates that respiratory problems may be associated with 3D printer emissions. CASE REPORT: The patient was a 28-year-old self-employed businessman with a past history of asthma in childhood, which had resolved completely by the age of eight. He started using 10 fused deposition modelling 3D printers with acrylonitrile-butadiene-styrene filaments in a small work area of approximately 3000 cubic feet. Ten days later, he began to experience recurrent chest tightness, shortness of breath and coughing at work. After 3 months, his work environment was modified by reducing the number of printers, changing to polylactic acid filaments and using an air purifier with an high-efficiency particulate air filter and organic cartridge. His symptoms improved gradually, although he still needed periodic treatment with a salbutamol inhaler. While still symptomatic, a methacholine challenge indicated a provocation concentration causing a 20% fall in FEV1 (PC20) of 4 mg/ml, consistent with mild asthma. Eventually, his symptoms resolved completely and a second methacholine challenge after symptom resolution was normal (PC20 > 16 mg/ml). CONCLUSIONS: This case indicates that workers may develop respiratory problems, including asthma when using 3D printers. Further investigation of the specific airborne emissions and health problems from 3D printing is warranted.

Comparison of clinic models for patients with work-related asthma.

BACKGROUND: Work-related asthma (WRA) is a prevalent occupational lung disease that is associated with undesirable effects on psychological status, quality of life (QoL), workplace activity and socioeconomic status. Previous studies have also indicated that clinic structure may impact outcomes among patients with asthma. AIMS: To identify the impact of clinic structure on psychological status, QoL, workplace limitations and socioeconomic status of patients with WRA among two different tertiary clinic models. METHODS: We performed a cross-sectional analysis between two tertiary clinics: clinic 1 had a traditional referral base and clinical staffing while clinic 2 entirely comprised Worker's Compensation System referrals and included an occupational hygienist and a return-to-work coordinator. Beck Anxiety and Depression II Inventories (BAI and BDI-II), Marks' Asthma Quality of Life Questionnaire (M-AQLQ) and Work Limitation Questionnaire (WLQ) were used to assess outcomes for patients with WRA. RESULTS: Clinic 2 participants had a better psychological status across the four instruments compared with clinic 1 (for Beck 'Anxiety': P < 0.001 and 'Depression': P < 0.01, 'Mood' domain of M-AQLQ: NS and 'Mental Demands' domain of WLQ: P < 0.01). Clinic 2 had a greater proportion of participants with reduced income. CONCLUSIONS: Our study indicates that clinic structure may play a role in outcomes. Future research should examine this in larger sample sizes.

Occupational hypersensitivity pneumonitis: an EAACI position paper.

The aim of this document was to provide a critical review of the current knowledge on hypersensitivity pneumonitis caused by the occupational environment and to propose practical guidance for the diagnosis and management of this condition. Occupational hypersensitivity pneumonitis (OHP) is an immunologic lung disease resulting from lymphocytic and frequently granulomatous inflammation of the peripheral airways, alveoli, and surrounding interstitial tissue which develops as the result of a non-IgE-mediated allergic reaction to a variety of organic materials or low molecular weight agents that are present in the workplace. The offending agents can be classified into six broad categories that include bacteria, fungi, animal proteins, plant proteins, low molecular weight chemicals, and metals. The diagnosis of OHP requires a multidisciplinary approach and relies on a combination of diagnostic tests to ascertain the work relatedness of the disease. Both the clinical and the occupational history are keys to the diagnosis and often will lead to the initial suspicion. Diagnostic criteria adapted to OHP are proposed. The cornerstone of treatment is early removal from exposure to the eliciting antigen, although the disease may show an adverse outcome even after avoidance of exposure to the causal agent.

Occupational anaphylaxis--an EAACI task force consensus statement.

Anaphylaxis is a systemic allergic reaction, potentially life-threatening that can be due to nonoccupational or, less commonly, to occupational triggers. Occupational anaphylaxis (OcAn) could be defined as anaphylaxis arising out of triggers and conditions attributable to a particular work environment. Hymenoptera stings and natural rubber latex are the commonest triggers of OcAn. Other triggers include food, medications, insect/mammal/snake bites, and chemicals. The underlying mechanisms of anaphylactic reactions due to occupational exposure are usually IgE-mediated and less frequently non-IgE-mediated allergy or nonallergic. Some aspects of work-related allergen exposure, such as route and frequency of exposure, type of allergens, and cofactors may explain the variability of symptoms in contrast to the nonoccupational setting. When assessing OcAn, both confirmation of the diagnosis of anaphylactic reaction and identification of the trigger are required. Prevention of further episodes is important and is based on removal from further exposure. Workers with a history of OcAn should immediately be provided with a written emergency management plan and an adrenaline auto-injector and educated to its use. Immunotherapy is recommended only for OcAn due to Hymenoptera stings.

EAACI position paper: irritant-induced asthma.

The term irritant-induced (occupational) asthma (IIA) has been used to denote various clinical forms of asthma related to irritant exposure at work. The causal relationship between irritant exposure(s) and the development of asthma can be substantiated by the temporal association between the onset of asthma symptoms and a single or multiple high-level exposure(s) to irritants, whereas this relationship can only be inferred from epidemiological data for workers chronically exposed to moderate levels of irritants. Accordingly, the following clinical phenotypes should be distinguished within the wide spectrum of irritant-related asthma: (i) definite IIA, that is acute-onset IIA characterized by the rapid onset of asthma within a few hours after a single exposure to very high levels of irritant substances; (ii) probable IIA, that is asthma that develops in workers with multiple symptomatic high-level exposures to irritants; and (iii) possible IIA, that is asthma occurring with a delayed-onset after chronic exposure to moderate levels of irritants. This document prepared by a panel of experts summarizes our current knowledge on the diagnostic approach, epidemiology, pathophysiology, and management of the various phenotypes of IIA.

Work-exacerbated asthma in a workers' compensation population.

BACKGROUND: Asthma is becoming more prevalent with large numbers of individuals suffering from work-exacerbated asthma. AIMS: To examine the characteristics of workplace exposures and working days lost in relation to work-exacerbated asthma (WEA) in a workers' compensation population. METHODS: An analysis of accepted workers' compensation asthma claims in Ontario over a 5-year period. Claims among the top three industry groups were categorized based on working time lost of 1 day or less, 2-5 days and 6 days or more. Attributable agents were subdivided into dusts, smoke, chemicals and sensitizers. RESULTS: Among the asthma claims, 72% (645) fulfilled criteria for WEA from their history. The commonest industry groups were services, education and health care, with 270 claims that met our analysis requirements. Within these industry groups, education had a lower proportion of workers with short exacerbations (missing 1 day or less: 27%) while the health care industry had a higher than expected proportion of short exacerbations (55%). The agents to which WEA was attributed differed across the groups, with dusts having the highest proportion in the education group (65%), smoke in the service industry (34%) and sensitizers in health care (41%). Those agents more commonly attributed to exacerbations tended to have lower rates of prolonged exacerbation compared with less commonly involved agents. CONCLUSIONS: The morbidity of WEA and the type of agents to which it was attributed varied between industry groups.

Asthma and exposure to cleaning products - a European Academy of Allergy and Clinical Immunology task force consensus statement.

Professional and domestic cleaning is associated with work-related asthma (WRA). This position paper reviews the literature linking exposure to cleaning products and the risk of asthma and focuses on prevention. Increased risk of asthma has been shown in many epidemiological and surveillance studies, and several case reports describe the relationship between exposure to one or more cleaning agents and WRA. Cleaning sprays, bleach, ammonia, disinfectants, mixing products, and specific job tasks have been identified as specific causes and/or triggers of asthma. Because research conclusions and policy suggestions have remained unheeded by manufactures, vendors, and commercial cleaning companies, it is time for a multifaceted intervention. Possible preventive measures encompass the following: substitution of cleaning sprays, bleach, and ammonia; minimizing the use of disinfectants; avoidance of mixing products; use of respiratory protective devices; and worker education. Moreover, we suggest the education of unions, consumer, and public interest groups to encourage safer products. In addition, information activities for the general population with the purpose of improving the knowledge of professional and domestic cleaners regarding risks and available preventive measures and to promote strict collaboration between scientific communities and safety and health agencies are urgently needed.

Occupational contact allergens: are they also associated with occupational asthma?

BACKGROUND: Workplace exposures that can potentially cause both allergic occupational contact dermatitis (AOCD) and occupational asthma (OA) are not clearly identified. METHODS: Occupational contact allergens (OCAs) were identified using North American Contact Dermatitis Group (NACDG) data. Reference documents and systematic reviews were used to determine whether each OCA had been reported to potentially cause OA. The presence or absence of a sensitizer notation in occupational hygiene reference documents was also examined. RESULTS: The 10 most common OCAs were: epoxy resin*, thiuram, carba mix, nickel sulfate*, cobalt chloride*, potassium dichromate*, glyceryl thioglycolate, p-phenylenediamine*, formaldehyde* and glutaraldehyde*. Seven (indicated by *) were determined to be possible causes of OA. Information on sensitizing potential from OH reference materials contained conflicting information. CONCLUSIONS: Several common OCAs can also potentially cause OA. Inhalation and dermal exposures to these agents should be controlled and both OA and AOCD should be considered as possible health outcomes. Increased consistency in sensitizer notations is needed.

Skin and respiratory symptoms among workers with suspected work-related disease.

BACKGROUND: Many workers are exposed to chemicals that can cause both respiratory and skin responses. Although there has been much work on respiratory and skin outcomes individually, there are few published studies examining lung and skin outcomes together. AIMS: To identify predictors of reporting concurrent skin and respiratory symptoms in a clinical population. METHODS: Patients with possible work-related skin or respiratory disease were recruited. An interviewer- administered questionnaire collected data on skin and respiratory symptoms, health history, smoking habits, workplace characteristics and occupational exposures. Predictors of concurrent skin and respiratory symptoms were identified using multiple logistic regression models adjusted for age, sex and atopy. RESULTS: In total, 204 subjects participated; 46% of the subjects were female and the mean age was 45.4 years (SD = 10.5). Most subjects (n = 167, 82%) had possible work-related skin disease, compared with 37 (18%) subjects with possible work-related respiratory disease. Subjects with a history of eczema (OR 3.68, 95% CI 1.7-7.8), those from larger workplaces (OR 2.82, 95% CI 1.8-7.4) and those reporting respirator use at work (OR 2.44, 95% CI 1.2-4.8) had significantly greater odds of reporting both work-related skin and respiratory symptoms. Current smoking was also associated with reporting concurrent skin and respiratory symptoms (OR 2.57, 95% CI 1.2-5.8). CONCLUSIONS: Workers reported symptoms in both systems, and this may be under-recognised both in the workplace and the clinic. The association between history of eczema and concurrent skin and respiratory symptoms suggests a role for impaired barrier function but needs further investigation.

EAACI position paper: prevention of work-related respiratory allergies among pre-apprentices or apprentices and young workers.

Apprenticeship is a period of increased risk of developing work-related respiratory allergic diseases. There is a need for documents to provide appropriate professional advice to young adults aiming to reduce unsuitable job choices and prevent impairment from their careers. The present document is the result of a consensus reached by a panel of experts from European and non-European countries addressed to allergologists, pneumologists, occupational physicians, primary care physicians, and other specialists interested in this field, which aims to reduce work-related respiratory allergies (rhinoconjunctivitis and asthma) among allergic or nonallergic apprentices and other young adults entering the workforce. The main objective of the document is to issue consensus suggestions for good clinical practice based on existing scientific evidence and the expertise of a panel of physicians.

Factors influencing respirator use at work in respiratory patients.

BACKGROUND: When engineering controls such as ventilation are not sufficient to prevent hazardous exposures in workplaces, respiratory protective devices (RPDs) may be provided to decrease workers' exposures. Often, workers do not use RPDs consistently when required. AIMS: Our goal was to determine important factors associated with RPD usage in workers with respiratory disease exposed to airborne hazards at work. METHODS: One hundred and twenty-nine respiratory clinic patients in jobs with self-identified hazardous airborne substances completed a questionnaire and their clinic files were reviewed. Statistical analysis using chi-squared test and binary logistical regression was done to identify associations with RPD usage. RESULTS: Forty-one per cent reported always wearing RPDs whenever a hazard was present; 33% never wore RPD. Compliance was highest among healthcare workers (72%) and lowest among workers in food and service industries (13 and 22%, respectively), P < 0.01. The compliance of co-workers, conveniently located RPDs, safety training discussing the use of RPDs, fit testing available at the workplace and age were positively associated with compliance (P < 0.05). Experiencing symptoms of shortness of breath and nasal stuffiness were negatively associated with compliance (P < 0.05). CONCLUSIONS: Addressing company factors and workers' symptoms apparently influencing compliance may optimize RPD usage.

Symptoms after mould exposure including Stachybotrys chartarum, and comparison with darkroom disease.

BACKGROUND: Mould-attributed symptoms have included features which overlap with unexplained syndromes such as sick building syndrome. OBJECTIVES: We describe questionnaire and chart review findings in patients following exposure to moulds which include Stachybotrys and compare responses with two control groups. METHODS: Thirty-two patients presented with symptoms attributed to mould exposures. Exposure identification for 25 patients had reported S tachybotrys chartarum as well as other mould (Aspergillus, Penicillium), 88% at work. The remaining seven had professionally visualized or self-reported/photographic exposure evidence only. A chart review was performed and a follow-up with a questionnaire, including questions on current health status, and nonspecific symptoms. RESULTS: Cough, shortness of breath and chest tightness (at presentation) were reported in 79%, 70% and 64%, respectively, and persisted >6 weeks in 91%. Skin test(s) were positive to fungal extract(s) in 30%. Seventeen returned questionnaires were obtained 3.1 (SD 0.5) years after the initial clinic assessment. Among this subgroup, persisting asthma-like symptoms and symptoms suggestive of sick building syndrome were frequent, and similar to a group previously assessed for darkroom disease among medical radiation technologists. The mould-exposed group more commonly reported they were bothered when walking in a room with carpets, complained of a chemical or metallic taste in their mouth, and had problems in concentration when compared with a control physiotherapist group (P < 0.005). CONCLUSIONS: Although only a minority with health concerns from indoor mould exposure had demonstrable mould-allergy, a significant proportion had asthma-like symptoms. Other symptoms were also common and persistent after the initial implicated exposure.

Work-associated irritable larynx syndrome.

BACKGROUND: Work-associated respiratory symptoms may be caused by disorders of both the lower and upper respiratory tract. We propose that occupational exposures may initiate and/or trigger recurrent hyperkinetic laryngeal symptoms, predominantly episodic dyspnoea, dysphonia, cough and sensation of tension in the throat-work-associated irritable larynx syndrome (WILS). AIMS: To examine characteristics of individual and work-related factors that are associated with WILS, occupational asthma (OA) and work-exacerbated asthma (WEA). METHODS: Subjects with WILS, OA and WEA were identified from an occupational lung disease clinic. A review of 448 charts of patients attending the clinic between 2002 and 2006 was undertaken, with information entered onto a standardized abstraction form. RESULTS: Fifty subjects were identified with OA, 40 with WEA and 30 with WILS. Subjects with the diagnosis of WILS were more likely to be female and more frequently reported symptoms of gastro-oesophageal reflux. The most common triggers of workplace symptoms in the WILS group were odours, fumes, perfumes and cleaning agents. Fourteen patients with WILS identified a specific precipitating event at the workplace at the time of the onset of their symptoms and five of these subjects presented to an emergency department within 24 h of the event. CONCLUSIONS: Dysfunction of the upper airway is an important cause of work-associated respiratory symptoms. The identification and management of WILS requires a multidisciplinary approach with a focus on modifying work-related and intrinsic factors that may perpetuate symptoms.

Irritant-induced occupational asthma.

A retrospective review was performed on the files of 154 consecutive workers assessed for occupational asthma to clarify the relative frequency of asthma induced by irritants in the workplace and to determine whether such asthma was clearly distinguishable from other forms of occupational asthma. Fifty-nine workers were considered to have occupational asthma. A subset of ten had a history consistent with asthma initiated by exposure to high concentrations of an irritant, had persistent symptoms for an average of five years when seen, demonstrated increased reactivity to methacholine, and gave no prior history of pulmonary complaints. These ten had a lower incidence of atopy (20 percent vs 58 percent) and a more frequent history of smoking (80 percent vs 38 percent) than the other subjects with occupational asthma but did not differ in average latency (5.9 years vs 5.7 years). Our findings suggest that irritant-induced asthma is not uncommon, and those affected may have different baseline characteristics from others with occupational asthma.

Outcome of assessments for occupational asthma.

Among 154 referrals to a university hospital clinic for assessment of possible occupational asthma, the feasibility and results of different investigations were assessed using a consistent approach to all patients. A positive skin test to a workplace allergen (14 percent of all subjects), positive peak flow workplace changes (12 percent), improvement in methacholine response on holiday (9 percent), and/or positive specific challenge testing (14 percent) supported the diagnosis of occupational asthma in 61 subjects (39 percent of the total referrals). Fifty-one of these were related to a workplace sensitizer and ten to a presumed irritant. Occupational asthma was excluded in 48 subjects (31 percent) who had normal methacholine responsiveness within 24 hours of work (22 percent of the 154 subjects), peak flow readings no worse at work than on holidays (14 percent of the total referrals) and/or negative specific challenge testing (10 percent of the total referrals). Insufficient information could be obtained for a diagnosis in the remaining 45 subjects (28 percent). No single investigation was considered diagnostic in this study, as each could be positive or negative for other reasons.

Peak expiratory flow rates in possible occupational asthma.

Objective criteria for interpretation of peak expiratory flow rate readings were assessed in 50 patients evaluated for suspected occupational asthma who had at least two weeks of PEFR readings and an objective diagnosis based on other investigations. The prevalence of OA was 36 percent. Peak flows were interpreted by two observers blinded to other results. Criteria for a PEFR interpretation of OA were as follow: diurnal variation greater than or equal to 20 percent relatively more frequently or with greater variation on working days than days off work. With the objective diagnoses as the gold standard, the sensitivity of the PEFR interpretations was 72 percent for OA; specificity for no asthma was 53 percent. Excluding those with greater than or equal to 20 percent variation on only one day sensitivity improved to 93 percent for OA, and specificity to 77 percent. There was an acceptable level of interobserver variation (kappa 62 to 83 percent). We conclude that simple objective criteria for PEFR interpretation can be developed with acceptable interobserver variation.

Immediate hypersensitivity to tuberculin. In vivo and in vitro studies.

Immediate responses of hypersensitivity to skin testing with purified derivative of tuberculin (PPD) were observed in 2.3 percent of 3,248 patients seen in an allergy clinic, and the relationship to delayed responses was questioned. Immediate cutaneous reactions to testing with PPD appeared in all age groups and occurred in nonatopic patients but were more common in atopic patients (p less than 0.005). Delayed cutaneous reactions to testing with PPD occurred in only three out of 76 patients with immediate reactivity. Antihistaminic suppression of immediate reactivity was not followed by evidence of delayed cutaneous reactivity. In vitro tests of lymphocytic stimulation revealed indices of stimulation with PPD to be similar both in patients with immediate and delayed cutaneous reactivity. Failure to manifest delayed cutaneous reactivity following immediate cutaneous reactions alone may be explained by antigen-antibody binding and phagocytosis, by suppressor T-lymphocytes, or by impaired release or lack of response to T-lymphocytic mediators. Adverse reactions to administration of BCG vaccine in patients with immediate cutaneous reactivity might be anticipated.