New occupational and environmental causes of asthma and extrinsic allergic alveolitis

Hypersensitivity Pneumonitis: Challenges of a Complex Disease

Hypersensitivity pneumonitis (HP) is a complex interstitial lung disease caused by chronic inhalation of a wide variety of antigens in susceptible and sensitized individuals, commonly associated with an occupational exposure. An impressive number of inciting antigens causing hypersensitivity pneumonitis have been found to cover a wide range of occupations. As working practices have changed over time, especially in industrialized countries, new names for occupational HP have emerged. This review emphasizes the main diagnostic issues arising from the high variability of clinical presentation and the broad spectrum of causal antigens. Furthermore, it provides an overview of current methods to unveil possible causes of hypersensitivity pneumonitis, highlights HP's current diagnostic and treatment challenges and the remaining areas of uncertainty, and presents prevention strategies.

A cross-sectional analysis of associations between environmental indices and asthma in U.S. counties from 2003 to 2012

BACKGROUND

To capture the impacts of environmental stressors, environmental indices like the Air Quality Index, Toxic Release Inventory, and Environmental Quality Index have been used to investigate the environmental quality and its association with public health issues. However, past studies often rely on relatively small sample sizes, and they have typically not adjusted for important individual-level disease risk factors.

OBJECTIVE

We aim to estimate associations between existing environmental indices and asthma prevalence over a large population and multiple years.

METHODS

Based on data availability, we assessed the predictive capability of these indices for prevalent asthma across U.S. counties from 2003 to 2012. We gathered asthma data from the U.S. CDC Behavioral Risk Factor Surveillance System by county and used multivariable weighted logistic regression models to estimate the associations between the environmental indices and asthma, adjusting for individual factors such as smoking, income level, and obesity.

RESULTS

Environmental indices showed little to no correlation with one another and with prevalent asthma over time. Associations of environmental indices with prevalent asthma were very weak; whereas individual factors were more substantially associated with prevalent asthma.

SIGNIFICANCE

Our study suggests that an improved environmental index is needed to predict population-level asthma prevalence.

Hypersensitivity pneumonitis in a slaughterhouse worker: A case report

This case report describes a 60-year-old male, who presented to the Respiratory Outpatient Unit due to dyspnea on exertion and persistent dry cough, worsened during the preceding 6 months. He was nonsmoker with an otherwise unremarkable medical history and had been working in a sheep/goat slaughterhouse for the last 25 years. He recalled a number of episodes of flu-like symptoms in the past that subsided without any specific treatment. Given the compatible occupational history, the radiologic pattern in chest High-Resolution Computed Tomography and the Bronchoalveolar Lavage subpopulation analysis, hypersensitivity pneumonitis was diagnosed, and the patient was advised to leave temporarily his current occupational activity. Four weeks later, clinical and functional improvement was observed. A permanent job change was subsequently suggested, and sustained improvement was confirmed during his follow-up at 3 months.

Hypersensitivity pneumonitis in a beautician

A 52-year-old non-smoking beautician using a skincare device spraying steam and ozone (a "vapozone" facial steamer) was referred for progressive dyspnea and dry cough during working periods. Although spirometry was normal, she had decreased diffusing capacity of the lung for carbon monoxide, bronchiolitis with air trapping on high-resolution CT scan and 60% lymphocytosis by bronchoalveolar lavage. Twenty-six antigens were tested and serum-specific precipitins were found mainly against Pseudomonas sp. and Mycobacterium mucogenicum. Cultures from her skincare device isolated Pseudomonas sp. Outcome was favorable with cessation of occupational exposure to the device, without any medication. This is the first report of a case of HP in a beautician due to steam contaminated by Pseudomonas sp. from a vapozone. HP, and not only asthma and contact dermatitis, should be suspected in beauticians with respiratory symptoms. Am. J. Ind. Med. 59:1041-1045, 2016. © 2016 Wiley Periodicals, Inc.

Chronic hypersensitivity pneumonitis

Hypersensitivity pneumonitis (HSP) is a common interstitial lung disease resulting from inhalation of a large variety of antigens by susceptible individuals. The disease is best classified as acute and chronic. Chronic HSP can be fibrosing or not. Fibrotic HSP has a large differential diagnosis and has a worse prognosis. The most common etiologies for HSP are reviewed. Diagnostic criteria are proposed for both chronic forms based on exposure, lung auscultation, lung function tests, HRCT findings, bronchoalveolar lavage, and biopsies. Treatment options are limited, but lung transplantation results in greater survival in comparison to idiopathic pulmonary fibrosis. Randomized trials with new antifibrotic agents are necessary.

Imaging of Occupational Lung Disease

Occupational lung diseases span a variety of pulmonary disorders caused by inhalation of dusts or chemical antigens in a vocational setting. Included in these are the classic mineral pneumoconioses of silicosis, coal worker's pneumoconiosis, and asbestos-related diseases as well as many immune-mediated and airway-centric diseases, and new and emerging disorders. Although some of these have characteristic imaging appearances, a multidisciplinary approach with focus on occupational exposure history is essential to proper diagnosis.

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.

Lung transplantation for hypersensitivity pneumonitis

BACKGROUND

Hypersensitivity pneumonitis (HP) is an inhaled antigen-mediated interstitial lung disease (ILD). Advanced disease may necessitate the need for lung transplantation. There are no published studies addressing lung transplant outcomes in HP. We characterized HP outcomes compared with referents undergoing lung transplantation for idiopathic pulmonary fibrosis (IPF).

METHODS

To identify HP cases, we reviewed records for all ILD lung transplantation cases at our institution from 2000 to 2013. We compared clinical characteristics, survival, and acute and chronic rejection for lung transplant recipients with HP to referents with IPF. We also reviewed diagnoses of HP discovered only by explant pathology and looked for evidence of recurrent HP after transplant. Survival was compared using Kaplan-Meier methods and Cox proportional hazard modeling.

RESULTS

We analyzed 31 subjects with HP and 91 with IPF among 183 cases undergoing lung transplantation for ILD. Survival at 1, 3, and 5 years after lung transplant in HP compared with IPF was 96%, 89%, and 89% vs 86%, 67%, and 49%, respectively. Subjects with HP manifested a reduced adjusted risk for death compared with subjects with IPF (hazard ratio, 0.25; 95% CI, 0.08-0.74; P = .013). Of the 31 cases, the diagnosis of HP was unexpectedly made at explant in five (16%). Two subjects developed recurrent HP in their allografts.

CONCLUSIONS

Overall, subjects with HP have excellent medium-term survival after lung transplantation and, relative to IPF, a reduced risk for death. HP may be initially discovered only by review of the explant pathology. Notably, HP may recur in the allograft.

Imaging in occupational and environmental lung disease

PURPOSE OF REVIEW

Work-related and environmental lung disease is increasing over time and new antigens causing pulmonary response are described in medical literature every year with more or less specific imaging findings. The purposes of this review are to highlight the current role of imaging, describe classic as well as uncommon high-resolution computed tomography (HRCT) patterns helpful in guiding diagnosis and update the recent literature on this topic.

RECENT FINDINGS

Recent literature on imaging of occupational and environmental lung disease is scarce and is predominantly based on the HRCT appearance related to specific antigen exposure and on prognostic significance of findings.

SUMMARY

Knowledge of imaging modality potential and radiologic appearance may guide identification, characterization and follow-up of old and new occupational and environmental lung diseases. HRCT plays a key role in this context, having radiation exposure as a major limitation, especially in asymptomatic patients. Low-dose HRCT has the potential to be employed for screening and surveillance of the exposed individuals. However, future research is needed to further this field.

Occupational hypersensitivity pneumonitis in a baker: a new cause

Bakers are exposed daily to flour and may be susceptible to immunologic occupational diseases. A 30-year-old, nonsmoking, female baker was referred for progressive dyspnea on exertion, basal crackles on auscultation, restrictive lung function, decreased diffusing capacity of the lung for carbon monoxide, ground glass hyperdensities with a mosaic pattern on high-resolution CT scan, 25% lymphocytosis by BAL, and cellular chronic bronchiolitis with peribronchiolar interstitial inflammation by lung biopsy specimen. Cultures from flours isolated nine species, including Aspergillus fumigatus. Twenty-six antigens were tested. Serum-specific precipitins were found against A fumigatus, the flour mite Acarus siro, and total extracts from maize and oat. Outcome was favorable with cessation of occupational exposure to flours and transient therapy with prednisone and immunosuppressive agents. To our knowledge, this report is the first of a well-documented case of hypersensitivity pneumonitis due to sensitization to fungi- and mite-contaminated flours. Hypersensitivity pneumonitis--and not only asthma and allergic rhinitis--should be suspected in bakers with respiratory symptoms.

Fungi: the neglected allergenic sources

Allergic diseases are considered the epidemics of the twentieth century estimated to affect more than 30% of the population in industrialized countries with a still increasing incidence. During the past two decades, the application of molecular biology allowed cloning, production and characterization of hundreds of recombinant allergens. In turn, knowledge about molecular, chemical and biologically relevant allergens contributed to increase our understanding of the mechanisms underlying IgE-mediated type I hypersensitivity reactions. It has been largely demonstrated that fungi are potent sources of allergenic molecules covering a vast variety of molecular structures including enzymes, toxins, cell wall components and phylogenetically highly conserved cross-reactive proteins. Despite the large knowledge accumulated and the compelling evidence for an involvement of fungal allergens in the pathophysiology of allergic diseases, fungi as a prominent source of allergens are still largely neglected in basic research as well as in clinical practice. This review aims to highlight the impact of fungal allergens with focus on asthma and atopic dermatitis.