Inhalation challenge test in the diagnosis of occupational rhinitis

Formaldehyde and asthma: a plausibility?

Formaldehyde (FA) is a ubiquitous indoor air pollutant emitted from construction, consumer, and combustion-related products, and ozone-initiated reactions with reactive organic volatiles. The derivation of an indoor air quality guideline for FA by World Health Organization in 2010 did not find convincing evidence for bronchoconstriction-related reactions as detrimental lung function. Causal relationship between FA and asthma has since been advocated in meta-analyses of selected observational studies. In this review, findings from controlled human and animal exposure studies of the airways, data of FA retention in the respiratory tract, and observational studies of reported asthma applied in meta-analyses are analyzed together for coherence of direct association between FA and asthma. New information from both human and animal exposure studies are evaluated together with existing literature and assessed across findings from observational studies and associated meta-analyses thereof. Retention of FA in the upper airways is > 90% in agreement with mice exposure studies that only extreme FA concentrations can surpass trachea, travel to the lower airways, and cause mild bronchoconstriction. However, taken together, detrimental lung function effects in controlled human exposure studies have not been observed, even at FA concentrations up 4 ppm (5 mg/m3), and in agreement with controlled mice exposure studies. Typical indoor FA concentrations in public buildings and homes are far below a threshold for sensory irritation in the upper airways, based on controlled human exposure studies, to induce sensory-irritative sensitization nor inflammatory epithelial damage in the airways. Analysis of the observational heterogeneous studies applied in the meta-analyses suffers from several concomitant multifactorial co-exposures, which invalidates a direct association with asthma, thus the outcome of meta-analyses. The evidence of a direct causal relationship between FA and asthma is insufficient from an experimental viewpoint that includes retention data in the upper airways and controlled animal and human exposure studies. Taken together, a coherence of controlled experimental findings with individual observational studies and associated meta-analyses, which suffer from caveats, is absent. Further, lack of identified evidence of FA-IgE sensitization in both experimental studies and observational studies agrees with indoor FA concentrations far below threshold for sensory irritation. The assessment of experimental data with uncontrolled observational studies in meta-analyses is incompatible with a direct causal relationship between FA and asthma or exacerbation thereof due to lack of coherence and plausibility.

Occupational Exposure of Hairdressers to Airborne Hazardous Chemicals: A Scoping Review

INTRODUCTION

Exposure to hazardous chemicals released during hairdressing activities from hair care products puts hairdressers at risk of adverse health effects. Safety assessments of hair products are mainly focused on consumers, but exposure for professional hairdressers might be substantially higher.

OBJECTIVE

To identify and assess available research data on inhalation exposures of professional hairdressers.

METHODS

A systematic search of studies between 1 January 2000 and 30 April 2021 was performed in Medline, Embase, Web of Science and in Cochrane registry, toxicological dossiers of the Scientific Committee on Consumer Safety (SCCS) of the European Commission as well as the German MAK Commission. Studies reporting quantitative data on airborne concentrations of chemicals in the hairdresser's workplace were considered. The outcome was an airborne concentration of chemicals in the working environment, which was compared, when possible, with current occupational exposure limits (OEL) or guidance levels.

RESULTS

In total, 23 studies performed in 14 countries were included. The average number of hairdressing salons per study was 22 (range 1-62). Chemicals most frequently measured were formaldehyde (n = 8), ammonia (n = 5), total volatile organic compounds (TVOC) (n = 5), and toluene (n = 4). More than fifty other chemicals were measured in one to three studies, including various aromatic and aliphatic organic solvents, hydrogen peroxide, persulfate, and particulate matter. Most studies reported environmental air concentrations, while personal exposure was measured only in seven studies. The measured air concentrations of formaldehyde, ammonia, and TVOC exceeded OEL or guidance values in some studies. There was large variability in measuring conditions and reported air concentrations differed strongly within and between studies.

CONCLUSION

Hairdressers are exposed to a wide spectrum of hazardous chemicals, often simultaneously. Airborne concentrations of pollutants depend on salon characteristics such as ventilation and the number of customers but also on used products that are often country- or client-specific. For exposure to formaldehyde, ammonia, and TVOC exceeding OELs or guidance values for indoor air was observed. Therefore, occupational exposure should be taken into account by safety regulations for hair care products.

Respiratory toxicity of persulphate salts and their adverse effects on airways in hairdressers: a systematic review

Objective

To review the literature on respiratory effects of persulfate salts (PS) or hair bleaches in hairdressers and animal models exploring mechanisms behind PS-induced asthma.

Methods

A systematic review according to the PRISMA guidelines was performed. Studies published from 2000 to July 2021 that fulfilled predefined eligibility criteria were retrieved. Data were not quantitatively synthesized due to the heterogeneity of study designs, outcomes and methods.

Results

Forty-two articles were included. PS are indicated as the main cause of occupational rhinitis and asthma in hairdressers, and one of the leading causes of occupational asthma in some European countries. Bleaching products are indicated as the most important factor for development of respiratory symptoms, lung function decline, and leaving the hairdressing profession. Risk estimates from a good quality prospective study showed up to 3.9 times higher risk for wheezing and breathlessness in hairdressers aged ≥ 40 years than in matched controls, and 20 times higher risk in hairdressers to develop respiratory symptoms from exposure to bleaching powder than controls. Pathophysiological mechanisms of the respiratory response to PS are not yet fully elucidated, but may include non-specific and specific immune responses.

Conclusions

Hairdressing is associated with a wide spectrum of respiratory adverse effects, of which bleaching products were indicated as the most hazardous. Preventive measures for reducing inhalatory exposure to PS in hair salons should be re-evaluated, including adopting occupational exposure limits at EU level, and encouraging use of safer bleach formulations.

PROSPERO registration number

CRD42021238118.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00420-022-01852-w.

Workplace exposure to wood dust and the prevalence of wood-specific sensitization

Wood is processed worldwide, and occupational exposure to wood dust is affecting millions of workers. Studies have identified wood dust as a risk factor for non-malignant respiratory diseases consistent with both an allergic and a non-allergic origin. This paper summarizes our current knowledge on the importance of specific sensitization among subjects occupationally exposed to wood dust. Specific sensitization to wood dust exists, but is probably of minor importance for most wood species. In order to move the research field forward increased focus on more standardized tools for specific IgE (sIgE) diagnostics is needed and more specific tools are necessary to identify clinical relevant cases of wood dust sensitization. Moreover epidemiological studies on the occurrence of sIgE-mediated sensitization in different populations of woodworkers are needed.

Quantification of obeche wood allergen: Development of a sensitive sandwich-ELISA for occupational exposure assessment

Obeche wood is a prominent cause of allergic occupational asthma. To reduce the risk of immunoglobulin E (IgE)-mediated sensitization it is important to assess airborne obeche wood allergen concentrations at exposed workplaces. Therefore, a highly sensitive obeche wood allergen immunoassay was developed and applicability was proven on airborne passive dust samples in Spanish wood workshops. Obeche wood sandwich enzyme-linked immunosorbent assay (ELISA) polyclonal antibodies (pAbs) were developed. Test specificity was verified by different wood and mold extracts. Obeche wood allergen monitoring was conducted in four Spanish wood workshops, including wood-dust-exposed and nonexposed areas inside and outside the workplaces, as well as controls. Dust was collected with electrostatic dust collectors (EDC). Measuring range of the obeche wood sandwich-ELISA was between 36 pg/ml and 1.6 µg/ml. The test system showed only marginal reactivity to other hardwoods and no reactivity to softwoods and molds. Obeche allergen was detected in all EDC from workplaces. The highest concentration was measured in the workshop with the longest obeche wood exposure (geometric mean [GM]: 7548 µg/m²); shorter obeche wood processing periods resulted in lower amounts of allergen (GM: 29 µg/m²). Obeche wood allergen transfer from exposed workplaces to nonexposed areas inside and outside the workshop was assessed. In control EDC from nonexposed facilities/homes no obeche wood allergen was found. The new obeche wood sandwich-ELISA is a valid tool to quantify obeche allergen exposure. Evidence indicates it will be possible to monitor obeche allergen exposure during different processes, as well as transfer effects in nonexposed areas.

Patterns of suspected wheat-related allergy: a retrospective single-centre case note review in 156 patients

Background

Allergy to wheat can present clinically in different forms: Sensitization to ingested wheat via the gastrointestinal tract can cause traditional food allergy or in combination with exercise, Wheat-Dependent Exercise-Induced Anaphylaxis (WDEIA). Sensitization to inhaled wheat flour may lead to occupational rhinitis and/or asthma.

Methods

We retrospectively reviewed the case notes of 156 patients (age 0.7 – 73.3 years) with a case history of wheat allergy. The population was divided into three groups, 1: Wheat allergy elicited by ingestion, 2: By inhalation and 3: WDEIA. All patients were examined with detailed case history, specific IgE (sIgE), Skin Prick Test (SPT) and wheat challenge (nasal or oral ± exercise). Details of the case history were extracted from the patients´ case records.

Results

Group 1: Twenty one of 95 patients were challenge positive (15 children, 6 adults). All children had atopic dermatitis, and most (13/15) outgrew their wheat allergy. Most children (13/15) had other food allergies. Challenge positive patients showed significantly higher levels of sIgE to wheat and significantly more were SPT positive than challenge negative.

Group 2: Eleven out of 13 adults with occupational asthma or rhinitis were challenge positive. None outgrew their allergy. Seven had positive sIgE and 10 had positive SPT to wheat.

Group 3: Ten of 48 (adolescent/adults) were positive when challenged during exercise. Challenge positive patients showed significantly higher levels of sIgE to ω-5-gliadin. The natural course is presently unknown.

Conclusion

Wheat allergy can manifest in different disease entities, rendering a detailed case history and challenge mandatory. Patient age, occupation, concomitant allergies (food or inhalant) and atopic dermatitis are important factors for evaluation.

Latex hypersensitivity among allergic Egyptian children: relation to parental/self reports

BACKGROUND

Latex allergy is one of the major health concerns and allergic reactions to latex may be serious and fatal.

PURPOSE

In this study, we sought to determine the frequency of latex hypersensitivity in a group of allergic Egyptian infants and children and its relation to the history provided by the patients or caregivers.

METHODS

We consecutively enrolled 400 patients with physician diagnosed allergic diseases. The study measurements included clinical evaluation for the site and duration of allergy, history suggestive of latex allergy, family history of allergy, and skin prick testing (SPT) using a commercial latex extract.

RESULTS

The study revealed that 16/400 (4%) patients had positive SPT; 11 of them only had positive history of sensitivity to latex. Positive latex SPT was reported in 3.4% (11/326) of patients with bronchial asthma, 5.9% (7/118) of patients with skin allergy, and 4.5% (2/44) of patients with allergic rhinitis. SPT was positive in 7.4% (4/54) of patients with concomitant respiratory and skin allergy. Latex SPT was more specific than sensitive (97.69% and 77.77%, resp.) with a negative predictive value of 99.47%.

CONCLUSION

Although underrecognized, latex is an important allergen in the pediatric age group with a sensitization frequency of 4% among allergic children. It was observed to be especially associated with multiple allergic diseases coexisting in the same patient. Pediatric allergologists should educate their patients on latex allergy and encourage the use of latex-free products.

Occupational asthma and occupational rhinitis: the united airways disease model revisited

OBJECTIVES

Whereas accumulating evidence indicates close associations between rhinitis and asthma, little is known about the relationships between occupational rhinitis (OR) and occupational asthma (OA). This study analyses the prevalence of OR associated with OA, globally and according to the various causal agents, and investigates the temporal relationships between these two conditions.

METHODS

Data on incident cases of OA (2008-2010) were collected through the French national occupational disease surveillance and prevention network, using a standardised form including information on occupation, causal agents, presence of OR, and respective dates of occurrence of rhinitis and asthma.

RESULTS

Among the 596 reported OA cases with latency period, 555 could be attributed to identified agents: high molecular weight (HMW) agents (n=174); low molecular weight (LMW) agents (n=381). Overall, OR was associated with OA in 324 (58.4%) cases. The frequency of association was significantly higher for HMW agents than for LMW agents (72.2% vs 51.5%, p<0.001). OR occurred before OA significantly more frequently for HMW agents than for LMW agents (p<0.01).

CONCLUSIONS

These results show that OR is frequently associated with OA, especially when HMW agents are involved. They are consistent with the hypothesis that OR, in conjunction with OA, is more likely to be caused by sensitisers that cause disease via IgE-mediated mechanisms and suggest that symptoms of OR should be taken into account in the medical surveillance of workers exposed to HMW agents.

Diagnostic tools in Rhinology EAACI position paper

This EAACI Task Force document aims at providing the readers with a comprehensive and complete overview of the currently available tools for diagnosis of nasal and sino-nasal disease. We have tried to logically order the different important issues related to history taking, clinical examination and additional investigative tools for evaluation of the severity of sinonasal disease into a consensus document. A panel of European experts in the field of Rhinology has contributed to this consensus document on Diagnostic Tools in Rhinology.

Non-cancer effects of formaldehyde and relevance for setting an indoor air guideline

There is considerable recent focus and concern about formaldehyde (FA). We have reviewed the literature on FA with focus on chemosensory perception in the airways and lung effects in indoor environments. Concentrations of FA, both personal and stationary, are on average in the order of 0.05 mg/m(3) or less in Europe and North America with the exception of new housing or buildings with extensive wooden surfaces, where the concentration may exceed 0.1 mg/m(3). With the eye the most sensitive organ, subjective irritation is reported at 0.3-0.5 mg/m(3), which is somewhat higher than reported odour thresholds. Objective effects in the eyes and airways occur around 0.6-1 mg/m(3). Dose-response relationships between FA and lung function effects have not been found in controlled human exposure studies below 1 mg/m(3), and epidemiological associations between FA concentrations and exacerbation of asthma in children and adults are encumbered by complex exposures. Neither experimental nor epidemiological studies point to major differences in susceptibility to FA among children, elderly, and asthmatics. People with personal trait of negative affectivity may report more symptoms. An air quality guideline of 0.1 mg/m(3) (0.08 ppm) is considered protective against both acute and chronic sensory irritation in the airways in the general population assuming a log normal distribution of nasal sensory irritation.

Occupational rhinitis and asthma: where do we stand, where do we go?

This review provides an overview of current and emerging issues regarding occupational rhinitis (OR) and occupational asthma (OA), focusing on studies discussing concepts and results that are relevant to both diseases. OA and OR are conditions that affect the upper and lower airways, are characterized by reduced airway caliber and hyperresponsiveness and by inflammation, and are caused by agents present in the workplace. To explain disease expression, research is moving from the T-helper type 1/type 2 cells paradigm to consider the contribution of diverse alternative pathways such as neural inflammation, a dysfunctional epithelial barrier, and autoimmune mechanisms, among others. Objective assessment of OR and OA has been improved and tested for research and, currently, clinical application. Further developments in the field of OR are expected to lead to more generalized clinical applications, following the example of what has been achieved for OA.

Thaumatin-like protein and baker's respiratory allergy

BACKGROUND

Baker's asthma and rhinitis are among the most common occupational diseases. Inhaled cereal flours, such as wheat, especially cause this disease.

OBJECTIVE

To identify and test in vivo clinically important wheat allergens in baker's respiratory allergy in a Finnish population.

METHODS

Potential wheat allergens were purified using chromatographic methods from salt-soluble protein extracts of wheat flour and were used in skin prick tests with serial 10-fold dilutions (0.5-0.005 mg/mL). Twenty patients with baker's rhinitis, asthma, or both participated in this study. All the patients had positive skin prick test reactions and specific IgE antibodies to wheat flour. The control group consisted of 10 healthy individuals. Molecular identities of purified wheat allergens were characterized using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and tandem mass spectrometry.

RESULTS

Allergen concentrations of 0.3-0.5 mg/mL revealed that 12 patients reacted to a-amylase inhibitor (alpha-AI), 9 to peroxidase I (PI), 9 to thaumatin-like protein (TLP), and 6 to lipid transfer protein 2G (LTP2G). Conversely, with allergen concentrations of 0.05 mg/mL, 5 patients responded to alpha-AI, 3 to PI, 4 to LTP2G, and 6 to TLP. Of these, TLP and LTP2G are now observed to be new allergens associated with baker's asthma.

CONCLUSIONS

In addition to the earlier-described alpha-AI and PI, TLP and LTP2G are important in vivo wheat allergens in baker's allergies in Finland. Further studies are needed to elucidate the role of these novel wheat allergens in respiratory disorders.

Noninvasive methods for assessment of airway inflammation in occupational settings

The present document is a consensus statement reached by a panel of experts on noninvasive methods for assessment of airway inflammation in the investigation of occupational respiratory diseases, such as occupational rhinitis, occupational asthma, and nonasthmatic eosinophilic bronchitis. Both the upper and the lower airway inflammation have been reviewed and appraised reinforcing the concept of 'united airway disease' in the occupational settings. The most widely used noninvasive methods to assess bronchial inflammation are covered: induced sputum, fractional exhaled nitric oxide (FeNO) concentration, and exhaled breath condensate. Nasal inflammation may be assessed by noninvasive approaches such as nasal cytology and nasal lavage, which provide information on different aspects of inflammatory processes (cellular vs mediators). Key messages and suggestions on the use of noninvasive methods for assessment of airway inflammation in the investigation and diagnosis of occupational airway diseases are issued.

Pilot study on acute voice and throat symptoms related to exposure to organic dust: preliminary findings from a provocation test

The aim of this pilot research was to investigate acute voice and throat symptoms related to organic dust exposure among nine subjects with suspected occupational rhinitis or asthma. Subjective voice and throat symptoms were recorded before and after an occupational exposure test. In addition, the study included perceptual assessment of subjects' voice samples recorded before and after the exposure tests. The results showed a number of (statistically) significant voice and throat changes in symptoms based on subjects' own assessments. These symptoms included a hoarse, husky, or tense voice, requiring an extra effort when speaking and difficulty in starting phonation (P < 0.05). Other significant symptoms included feeling of shortness of breath or the need to gasp for air and feeling that the voice is weak or that it does not resonate (P < 0.01). Such changes were not, however, detected by voice clinicians in the listening test of subjects' voice samples recorded before and after the exposure. These results suggest that the larynx reacts to organic dust with symptoms that are felt by the patient rather than heard by the voice clinician. The voice disorder in such cases is a diagnosis based on symptoms expressed by subjects.