[Workplace-associated fever]

INTRODUCTION

Febrile conditions often have an infectious etiology. However, there are also fevers associated with occupational exposures. A detailed occupational history can hold the key to the diagnosis. In the case of exposure to organic dusts, the development of hypersensitivity pneumonitis (HP) is possible. Thus, HP should be considered in the presence of interstitial lung disease of unclear etiology. Failure to recognize this can have dramatic consequences and, in extreme cases, lead to lung transplantation. Differentially, organic dust toxic syndrome (ODTS) must be considered. The syndrome of metal fume fever provoked by inhalation of inorganic substances is usually benign and self-limiting. The disease manifests with fever, cough, and flu-like sensations.

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.

Bird ownership and pulmonary outcomes apart from hypersensitivity pneumonitis in European older adults

BACKGROUND

Exposure to birds has been linked with several lung pathologies and especially hypersensitivity pneumonitis, but discordant literature exist on the potential effects of this exposure on other respiratory pathologies.

AIM

This study aims to examine the associations between bird ownership and asthma, lung cancer, and chronic obstructive pulmonary disease (COPD) in older European adults.

METHODS

A total of 28,109 participants from the Survey of Health, Ageing, and Retirement in Europe were employed and analyzed with multivariate logistic regressions.

RESULTS

No association was found with asthma or lung cancer. Bird ownership increased the odds for COPD diagnosis (OR=1.30; 95 % CI: 1.12-1.51) and more so in males (OR=1.53; 95 % CI: 1.25-1.87) after adjustment for demographic, respiratory, lifestyle, and socioeconomic factors. Male bird owners who smoke had an even more increased risk compared to non-smokers, as did those who lived in multi-person households compared to those living alone.

CONCLUSION

Bird ownership may be positively associated with COPD in older European males.

Moldy Hazelnut Husk and Shell Related Hypersensitivity Pneumonitis: A Possible Novel Occupational Causative Agent

Hypersensitivity pneumonitis (HP) is a complex immune-mediated interstitial lung disease (ILD) triggered by inhalation exposure to environmental or occupational antigens in genetically susceptible individuals. Novel exposure sources and antigens are frequently identified. However, the causative agent remains unidentified in nearly half of HP cases. Early diagnosis for nonfibrotic-HP and quitting the exposure may prevent the disease progression to fibrotic forms and related complications. Here, we present two cases of HP associated with mold exposure in hazelnut husks, leaves, and shells in hazelnut agriculture.

Recurrent episodes of febrile dyspnoea: hypersensitivity pneumonitis caused by a household ultrasonic humidifier

Hypersensitivity pneumonitis is an immune-mediated interstitial lung disease that presents with respiratory symptoms, with or without systemic symptoms, following exposure to an identified or unidentified external factor. It can be caused by extrinsic factors including household items such as ultrasonic humidifiers.We present an intriguing case of a previously healthy 50-year-old man who displayed recurrent episodes of progressive dyspnoea and fever after repeated exposure to his household ultrasonic humidifier. He was treated with corticosteroids, followed by the removal of the humidifier, resulting in total recovery and absence of recurrence of further episodes.The clinical presentation of hypersensitivity pneumonitis can be dramatic, and the differential diagnosis is broad. The correct diagnosis is achieved by combining clinical, radiological and histopathological patterns. The key to finding the aetiology lies in a thorough history, with an important role for household investigations to identify the external factor.

Occupational hypersensitivity pneumonia

Hypersensitivity pneumonitis (HP) is an immunological lung disease that affects individuals who are sensitive and susceptible to occupational and environmental exposures. While clinical and radiological findings may resemble other interstitial lung diseases, identifying the causative agents can aid in the differential diagnosis. However, this can be challenging and may result in delayed diagnosis and poor prognosis. A gold standard test for diagnosis is currently unavailable, and therefore, a multidisciplinary approach involving a clinician, radiologist, and pathologist is necessary. Avoiding exposure is the first step in treatment, with immunosuppressive therapeutics also being used. Antifibrotic agents show promise for future treatment approaches. Despite recent advancements in data and guidelines, knowledge about managing occupational HP remains limited. This review provides a summary of the epidemiological, clinical, and radiological findings, as well as diagnostic and treatment principles of occupational HP based on current literature.

Inhalational lung diseases

The term inhalational lung disease comprises a group of entities that develop secondary to the active aspiration of particles. Most are occupational lung diseases. Inhalational lung diseases are classified as occupational diseases (pneumoconiosis, chemical pneumonitis), hypersensitivity pneumonitis, and electronic-cigarette-associated lung diseases. The radiologic findings often consist of nonspecific interstitial patterns that can be difficult to interpret. Therefore, radiologists' experience and multidisciplinary teamwork are key to ensure correct evaluation. The role of the radiologist is fundamental in preventive measures as well as in diagnosis and management, having an important impact on patients' overall health. It is crucial to take into account patients' possible exposure to particles both at work and at home.

Lung fibrosis in autoimmune diseases and hypersensitivity: how to separate these from idiopathic pulmonary fibrosis

Lung involvement in autoimmune diseases (AID) is uncommon, but may precede other organ manifestations. A diagnostic problem is chronicity presenting with lung fibrosis. A new category of interstitial pneumonia with autoimmune features for patients with clinical symptoms of AID and presenting with usual interstitial pneumonia (UIP) enables antifibrotic treatment for these patients. Hypersensitivity pneumonia (HP) and other forms of lung fibrosis were not included into this category. As these diseases based on adverse immune reactions often present with unspecific clinical symptoms, a specified pathological diagnosis will assist the clinical evaluation. We aimed to establish etiology-relevant differences of patterns associated with AID or HP combined with lung fibrosis. We retrospectively evaluated 51 cases of AID, and 29 cases of HP with lung fibrosis, and compared these to 24 cases of idiopathic pulmonary fibrosis (UIP/IPF). Subacute AID and HP most often presented with organizing pneumonia (OP), whereas chronicity was associated with UIP. Unspecified fibrosis was seen in a few cases, whereas NSIP pattern was rare. In 9 cases, the underlying etiology could not be defined. Statistically significant features differentiating chronic AID or HP from UIP/IPF are lymphocytic infiltrations into myofibroblastic/fibroblastic foci. Other features significantly associated with AID and HP were granulomas, isolated Langhans giant cells, and protein deposits, but seen in only a minority of cases. A combination of UIP with one of these features enabled a specific etiology-based diagnosis. Besides the antifibrotic drug regimen, additional therapies might be considered.

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.

COVID 19 - Possible interrelations with respiratory comorbidities caused by occupational exposure to various hazardous bioaerosols. Part I. Occurrence, epidemiology and presumed origin of the pandemic

The occupational bioaerosols containing viruses, bacteria, fungi, microbial toxins and plant or animal particles, may evoke infectious, allergic or immunotoxic diseases which may co-exist as comorbidities with COVID-19 and exacerbate the course of disease. They include hypersensitivity pneumonitis (HP) caused mostly by bacteria, fungi, and particles containing animal proteins, and immunotoxic diseases such as organic dust toxic syndrome (ODTS) and byssinosis, caused mostly by bacterial and fungal toxins. The two most probable scenarios of possible interrelations between these three comorbidities (CM) and COVID-19 are: 1) 'Triggering' - when infection with SARS-CoV-2 triggers severe CM after bioaerosol exposure; 2) 'Reverse triggering' when exposure to bioaerosol exacerbates a symptomless or mild course of COVID-19, and evokes a severe disease. The occupations mostly endangered by COVID-19 as the result of exposure to SARS-CoV-2 bioaerosol, or to other bioaerosols which may exacerbate this disease, include: health care workers, social workers, breeders of fur animals, slaughterhouse workers, workers engaged in the processing and selling of seafood, and probably also agricultural workers, mainly in the developing countries. The authors present a hypothesis for the origin of the present pandemic. It assumes that a mild form of the present SARS-CoV-2 that is supposedly circulating among the Chinese population in the eastern part of the country, mutated under the influence of as yet unknown factor(s) present in the Chinese seafood markets, probably component(s) of bioaerosols, into the virulent and highly contagious form, known as the present SARS-CoV-2, under a scenario similar to that the authors have named 'Reverse triggering'.

[The effect of air pollution in diffuse interstitial lung disease]

Few studies have examined the effects of air pollution in diffuse interstitial lung disease and they have focused on small numbers of patients. Most data are available in idiopathic pulmonary fibrosis and studies suggest that the level of exposure to pollutants may influence the development of acute exacerbations (ozone and NO₂), their incidence (NO₂), decline in respiratory function (PM₁₀) and death (PM₁₀ and PM_2.5). Several studies show an increase in the incidence of rheumatoid arthritis in people living near busy roads. In systemic scleroderma, hypersensitivity pneumonitis and sarcoidosis although negative effects of pollution have been reported the data are insufficient to be conclusive. Nevertheless, the observed effects of air pollution are consistent with those described for other chronic respiratory diseases. Exposure to pollution induces oxidative stress, chronic inflammation and shortening of telomeres, which are all mechanisms described in fibrogenesis. New epidemiological studies are needed with individual measurements of exposure to outdoor and indoor pollution, as well as fundamental studies to clarify the effect of pollution on fibrogenesis.

[ALLERGIC ALVEOLITIS [ARTICLE IN POLISH]]

Allergic alveolitis (AA) is a group of diseases with an immunologic background evoked by chronic antigen inhalation. The diagnosis is difficult due to the diversity and non-specific character of symptoms and different clinical severity. AA is the third most often interstitial-lung-disease, comprising 4-15% of all interstitial diseases. It's often related to professional exposure. Farmer's lung, a hypersensitivity pneumonitis is the most common AA. By binding precipitins to form immunologic complexes, antigens trigger an early phase acute reaction in the lung tissue thus initiating disease's progression. In the chronic phase endolobular fibrosis located in the upper lobes prevails. Disease differs in course depending the type and time of antigen exposition. Thus, avoiding antigen exposition is the first-line-therapy. Acute form is characterized by fever, chills, dyspnea, and cough. It usually starts 4-8 hours after intensive exposure. Early diagnosis leads to a good prognosis. When the exposition to the antigen stops, acute form of AA usually self-limits within 24-48 hours. Only in severe cases 0.5-1.0 mg/kg/d (up 60 mg/d) can be required for 1-2 weeks with a subsequent dose reduction. Long-term usually leads to chronic form with more serious deteriorations, including severe dyspnea and chronic cough (it takes months-years for them to develop, however). There is no effective therapy, in rapidly progressing cases 40-60 mg/g of prednisone repeated in 4-week-cycles can be recommended. Usually it does not stop the progression, and pulmonary fibrosis followed by respiratory insufficiency develop. Symptoms duration at diagnosis and effectiveness of antigen elimination are the known prognostic factors.

Acute hypersensitivity pneumonitis in woodworkers caused by inhalation of birch dust contaminated with Pantoea agglomerans and Microbacterium barkeri

CASE DESCRIPTION

Five workers (2 males and 3 females) employed in a furniture factory located in eastern Poland developed hypersensitivity pneumonitis (HP) after the pine wood used for furniture production was replaced by birch wood. All of them reported onset of respiratory and general symptoms (cough, shortness of breath, general malaise) after inhalation exposure to birch dust, showed crackles at auscultation, ground-glass attenuations in HRCT examination, and lymphocytosis in the BAL examination. The diagnosis of acute HP was set in 4 persons and the diagnosis of subacute HP in one.

IDENTIFICATION OF SPECIFIC ALLERGEN

Samples of birch wood associated with evoking disease symptoms were subjected to microbiological analysis with the conventional and molecular methods. Two bacterial isolates were found to occur in large quantities (of the order 10⁸ CFU/g) in examined samples: Gram-negative bacterium of the species Pantoea agglomerans and a non-filamentous Gram-positive actinobacterium of the species Microbacterium barkeri. In the test for inhibition of leukocyte migration, 4 out of 5 examined patients showed a positive reaction in the presence of P. agglomerans and 2 in the presence of M. barkeri. Only one person showed the presence of precipitins to P. agglomerans and none to M. barkeri. In the inhalation challenge, which is the most relevant allergological test in the HP diagnostics, all patients reacted positively to P. agglomerans and only one to M. barkeri. The results indicate that P. agglomerans developing in birch wood was the main agent causing HP in the workers exposed to the inhalation of dust from this wood, while the etiologic role of M. barkeri is probably secondary.

CONCLUSION

The results demonstrate that apart from fungi and filamentous actinobacteria, regarded until recently as causative agents of HP in woodworkers, Gram-negative bacteria and non-filamentous actinobacteria may also elicit disease symptoms in the workers processing wood infected with large amounts of these microorganisms. The results obtained also seem to indicate that cellular-mediated reactions are more significant for causing disease symptoms compared to those that are precipitin-mediated.

[Occupational exposures should be considered in all patients with non-malignant respiratory diseases]

Occupational exposures to gas, fumes, dust and chemicals contribute to non-malignant respiratory diseases like asthma, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis and community-acquired pneumonia in more than one in ten patients. They may be sick due to inhaling various particles, gases, fumes, or chemicals in the workplace. Hence, these exposures should be considered in all patients with non-malignant respiratory diseases. In an international literature review the occupational burden of asthma was 16%, chronic obstructive pulmonary disease 14%, idiopathic pulmonary fibrosis 26% and community-acquired pneumonia 10%.

Serum CXCL9 and CCL17 as biomarkers of declining pulmonary function in chronic bird-related hypersensitivity pneumonitis

The clinical course of chronic hypersensitivity pneumonitis (HP) with fibrosis is similar to that of idiopathic pulmonary fibrosis (IPF). Current research is expected to identify biomarkers effective in predicting the deterioration of lung function in a clinical setting. Our group analyzed the relationships between the following parameters in chronic bird-related HP: patient characteristics, serum markers, lung function, HRCT findings, BALF profiles, and the worsening of lung function. We also analyzed serum levels of CXCL9, CCL17, and Krebs von den Lungen 6 (KL-6) as serum markers. Patients showing declines in vital capacity (VC) of over 5% at 6 months after first admission were categorized as the “decline group”; the others were categorized as the “stable group.” The serum level of CCL17 and the percentage of BALF macrophages were significantly higher in the decline group compared to the stable group. Serum levels of CXCL9 and CCL17 were significant variables in a multivariate logistic regression analysis of factors associated with VC decline. Patients with a chemokine profile combining lower serum CXCL9 and higher serum CCL17 exhibited significantly larger VC decline in a cluster analysis. Higher serum CCL17 and lower serum CXCL9 were important predictors of worsening lung function in patients with chronic bird-related HP.

A rare association of cutaneous leukocytoclastic angiitis (hypersensitivity vasculitis) and hypersensitivity pneumonia (extrinsic allergic alveolitis) in a pigeon breeder - case report and literature review

Extrinsic allergic alveolitis is an occupational condition intensively studied and published about, unlike cutaneous leukocytoclastic angiitis. The coexistence of these two diseases is even more rare in the same patient with exposure to occupational pollutants of animal origin. We present the case of a 44-year-old man, a pigeon breeder admitted to hospital with a pruritic purpuric eruption and lower limb paresthesia, dyspnea on exertion, polymyalgia rheumatica, mixed polyarthralgias. Based on the clinical, paraclinical and laboratory investigations (electroneuromyography, plethysmography, computed tomography scan, musculocutaneous biopsy, current laboratory tests and immunoassays), the main diagnoses of extrinsic allergic alveolitis and leukocytoclastic vasculitis were determined. The patient underwent treatment with corticosteroids with a favorable outcome, but which becomes aggravated by the occurrence of necrotic skin lesions at the cessation of corticosteroid therapy on the patient's own initiative. After the resumption of the corticosteroid therapy, the lesions and symptoms improve. To our knowledge, this case report is the first one that describes an association of two major conditions, extrinsic allergic alveolitis and cutaneous leukocytoclastic angiitis, in the same clinical context of an occupational exposure to specific pollutants. Long-term corticosteroid therapy has proved to be useful in preventing relapses and improving the patient's clinical status with the association of cutaneous leukocytoclastic angiitis and extrinsic allergic alveolitis. Considering our findings in this case report, we may suggest the inclusion of systemic vasculitis on the list of recognized professional diseases.

Marijuana medusa: The many pulmonary faces of marijuana inhalation in adolescent males

Marijuana use has risen dramatically over the past decade. Over this same time period, pediatric hospitals have seen an increase in presentation of adolescents with acute respiratory symptoms after recent marijuana inhalation. We report a case series of three adolescent males with significant findings of bilateral pulmonary nodules and ground glass opacities on chest imaging associated with recent marijuana inhalation. Lung biopsies in two of the three patients confirmed silica-induced pneumoconiosis. The third patient was diagnosed with acute hypersensitivity pneumonitis without lung biopsy. Improvement in clinical symptoms and lung function testing were noted in two of three patients after marijuana inhalation cessation. This case series highlights the variety of severe pulmonary presentations in adolescents following recent marijuana inhalation. Future studies are required to assess whether these presenting pulmonary complications are from direct marijuana exposure or indirect associations with marijuana inhalation injuries.

Radiation Pneumonitis with Eosinophilic Alveolitis in a Lung Cancer Patient

A 59-year-old woman suffering from dry cough and dyspnea was admitted to our hospital. She had undergone concurrent chemo-radiotherapy five months earlier. Chest computed tomography revealed bilateral ground-glass opacities extending outside the irradiated lung field. Her eosinophil numbers were increased in both the peripheral blood and the bronchoalveolar lavage fluid; therefore, she was diagnosed with radiation pneumonitis accompanied by eosinophilic alveolitis. Steroid therapy promptly improved the pneumonitis. Radiation pneumonitis accompanied by eosinophilic alveolitis extending outside the irradiated field is rare. Bronchoalveolar lavage is useful for a diagnosis, and steroid therapy is effective for treatment.

Hypersensitivity pneumonitis due to unclean continuous positive airway pressure equipment

Hypersensitivity pneumonitis is a potentially fatal immunological lung disease caused by occupational or environmental exposure to specific antigens. Here, we report on an obstructive sleep apnea patient whose hypersensitivity pneumonitis was aggravated because of the use of unclean continuous positive airway pressure equipment. This report shows that careful history taking is important when diagnosing hypersensitivity pneumonitis. Sleep specialists should be aware of the risks related to unclean continuous positive airway pressure equipment use, and obstructive sleep apnea patients should be instructed and monitored in the regular cleaning of their equipment.

[Extrinsic allergic alveolitis: minimum for clinical practice]

Extrinsic allergic alveolitis (EAA) represent a group of diseases, that develop in susceptible individuals after repeated exposure to usually organic inhalation antigen. Patient may be in contact with these agents both in occupational and in home environment, as well as during free time activities and hobbies. The course of the disease is highly variable - EAA may have dramatic symptoms with fever, cough and severe dyspnoea as well as may be presented with slowly increasing dyspnoea and chronic cough. The more inconspicious are the symptoms of chronic EAA, the more problematic its treatment may be. Treatment options must be sought individually and respect potential risks and benefits for the patient. Avoiding further contact with offending antigens as well as optimizing patients nutritional status and starting pulmonary rehabilitation should be emphasized.Key words: corticosteroids - extrinsic allergic alveolitis - environmental exposure.

Hypersensitivity Pneumonitis Caused by a Home Ultrasonic Humidifier Contaminated with Candida guilliermondii

We herein report the first documented case of acute hypersensitivity pneumonitis in which Candida guilliermondii was the possible causative organism. A young Japanese woman presented to our hospital with relapsing respiratory symptoms accompanied by high fever. A detailed interview revealed that the onset of the symptoms occurred shortly after using a humidifier in her home. Her symptoms showed spontaneous improvement soon after admission, and an examination of her bronchoalveolar lavage fluid revealed the specific infiltration of inflammatory cells, which predominantly consisted of lymphocytes. Precipitin testing showed a positive reaction to C. guilliermondii, which was isolated from the home humidifier. Repeated history taking is essential for diagnosing occult respiratory disorders.

Fatal hypersensitivity pneumonitis after chemical occupational exposure

Hypersensitivity pneumonitis (HP; extrinsic allergic alveolitis) is a rare non-immunoglobulin E (IgE)-mediated inflammatory lung disease caused by inhalation exposure (occupational, recreational or ordinary home exposure). A 36-year-old female patient, without significant medical history, is referred to an outpatient pulmonology clinic for dry cough, shortness of breath, fever, fatigue and weight loss. Chest high-resolution computed tomography (HRCT) was performed, and significant lung fibrosis (especially centrilobular and interlobular in bilateral "thick lines"), traction bronchiectasis and alveolitis in both superior lobes are described. Lung function tests showed severe restrictive dysfunction. Transfer factor of the lung for carbon monoxide (TLCO) being very low, the flexible bronchoscopy was contraindicated. Surgical lung biopsy was performed. Histopathological examination showed characteristic lesions of chronic bilateral hypersensitivity pneumonitis. The patient died four days after the surgical intervention due to post-operative complications. Exposure to various chemical substances can form bonds with human proteins molecules and induce an exaggerated immune response in susceptible individuals. A high index of suspicion of occupational exposure can determine an early diagnosis with a better outcome.

The Relationship between the Incidence of Summer-type Hypersensitivity Pneumonitis and Environmental Factors in Southern Tochigi Prefecture

Objective Environmental and climatic changes have been occurring throughout the past 20 years in Japan. Correspondingly, the antigens that cause hypersensitivity pneumonitis might be changing. In an epidemiological survey of Japan in the 1980s, summer-type hypersensitivity pneumonitis (SHP) accounted for 74.4% of the cases of hypersensitivity pneumonitis. The epidemiological characteristics of this disease have not been reported since then. We investigated the annual changes in the number of cases of SHP and the factors affecting the results. Methods Cases that were diagnosed as SHP were retrieved from the medical records of our institute between 1990 and 2015. The diagnostic criteria proposed by the Japanese Ministry of Health, Labour and Welfare in 1990 were applied to obtain the definite diagnosis. Patients The study population included 25 diagnosed patients, including one intrafamilial case. The subjects were predominantly non-smoking women in their 50s and all lived in wooden houses that had been constructed more than 10 years previously. Results The number of cases that were diagnosed as SHP tended to decrease during the study period. However, temporal increases tended to occur in years with increased rainfall and decreased daylight hours. No relationship appeared to exist between the number of cases and high temperatures or humidity levels. Conclusion The incidence of SHP currently appears to be decreasing; however, the weather conditions in any given year might cause a temporal increase in the incidence rate.

Familial Summer-type Hypersensitivity Pneumonitis: A Review of 25 Families and 50 Cases in Japan

Summer-type hypersensitivity pneumonitis (SHP) is the most common form of pneumonitis in Japan; it accounts for 74% of all cases. It has been reported that 19.5-23.8% of SHP cases occur in families who live in the same house. We present our SHP cases and review 50 familial cases in 23 families that were reported in Japan (including our own) and 48 cases that were previously described in 22 articles published between January 1982 and October 2011. To the best of the authors' knowledge, this is the first review article in English to document the familial occurrence of SHP in Japan.

Japanese Guideline for Occupational Allergic Diseases 2014

In 2013, a guideline for occupational allergic diseases was published for the first time in Japan. Occupational allergic diseases are likely to worsen or become intractable as a result of continuous exposure to high concentrations of causative antigens, and are socioeconomically important diseases with which the patients might sometimes lose jobs due to work interruptions. Guidelines for occupational allergic diseases have been published in many countries. This guideline consists of six chapters about occupational asthma, occupational allergic rhinitis, occupational skin diseases, hypersensitivity pneumonitis and occupational anaphylaxis shock, and legal aspects of these diseases. The guideline is characterized with the following basic structure: Clinical Questions (CQs) are set with reference to Minds (Medical Information Network Distribution Service), statements by the committee are correspondingly listed, recommended grades and evidence levels are defined, and then descriptions and references are indicated.

Hypersensitivity Pneumonitis: A Comprehensive Review

Hypersensitivity pneumonitis (HP), also known as extrinsic allergic alveolitis, is a complex pulmonary syndrome mediated by the immune system and caused by inhalation of a wide variety of antigens to which the individual has been previously sensitized. The pathobiology of the disease is not fully understood, but in addition to the triggers that initiate the disease, host/genetic factors are likely to be important, as only a minority of exposed individuals develop HP. Due to the lack of a diagnostic gold standard, the diagnosis of HP is not straightforward and relies on the integration of a number of factors, including history of exposure, precipitating antibodies to the offending antigen, clinical features, bronchoalveolar lavage, and radiological and pathologic features. However, in the appropriate setting, a high index of suspicion is critically important and may obviate the need for more invasive tests. Clinical presentation and natural history vary widely. Acute forms generally resolve without sequelae, while chronic forms, which are caused by persistent low-grade exposures, are associated with poor prognosis. Corticosteroids may be useful in acute episodes for symptomatic relief or in chronic and progressive disease, but their long-term efficacy has never been validated in prospective clinical trials. Ideally, patients with HP should be referred to centers with expertise, as the overlap with other forms of interstitial lung disease may be substantial. Making the correct diagnosis has critical therapeutic and prognostic implications.

Hypersensitivity pneumonitis in a cluster of sawmill workers: a 10-year follow-up of exposure, symptoms, and lung function

BACKGROUND

The long-term prognosis of repeated acute episodes of hypersensitivity pneumonitis (HP) is not well described. We report on a 10-year follow-up of a 10-person cluster from a Norwegian sawmill who had all experienced relapsing episodes of HP.

OBJECTIVES

To evaluate the health symptoms, work-related sick-leave, and lung function of 10 workers exposed to mold in a Norwegian sawmill.

METHODS

Participants were evaluated at baseline and 10 years later at follow-up. A structured interview, measurement of serum IgG antibodies to Rhizopus microsporus (R. microsporus) antigens, lung function tests, high resolution computed tomography (HRCT) of the chest, and personal measurements of exposure to mold spores and dust were completed for each participant.

RESULTS

At baseline, nearly all workers reported acute episodes of HP more than twice a month. At follow-up, both the frequency and intensity of symptoms had declined. Sick-leave was reduced and gas diffusing capacity improved - paralleling the gradually reduced air levels of mold spores.

CONCLUSIONS

In spite of an initially high occurrence of symptoms, long-term clinical and physiological outcome was good. With reduced exposure to mold spores, symptoms declined and lung function was restored.

[Clinical morphology of hypersensitivity pneumonitis]

The article presents a viewpoint on morphogenesis types of dust pulmonary diseases and details clinical morphology of hypersensitivity pneumonitis, based on lung biopsy studies in industrial workers.

[The problems of classification of the occupational interstitial lung diseases, approaches to solving]

The analysis of the applied in Russia classifications of pneumoconiosis and occupational hypersensitivity pneumonitis in relation to the international classifications of occupational lung diseases and the classification of interstitial lung diseases (ILD) was performed. The necessity of a new approach to the classification of occupational ILD was proved and solutions of the problem were offered.

[Hypersensitivity pneumonitis-like disease caused by exposure to Mycobacterium avium complex in bathtub water at home: a case report]

We report here a case of hypersensitivity pneumonitis-like disease in an adult, likely due to exposure to Mycobacterium avium complex (MAC) in his bathtub water at home. A 63-year-old man was referred to our hospital with exertional dyspnea. Chest computed tomography showed bilateral, diffuse, centrilobular ground-glass nodules. Bronchoalveolar lavage showed marked lymphocytosis. Transbronchial biopsy showed epithelioid cell granulomas and lymphocyte alveolitis. Cultures of the patient's sputum and bathtub water yielded MAC. Variable-number tandem repeat analysis of the MAC strains in the sputum and bathtub water samples showed that the strains were genetically identical. The clinical condition of the patient improved at home under chemotherapy by avoiding the use of the bathtub.

Chapter 19: Hypersensitivity pneumonitis

Hypersensitivity pneumonitis (HP), also referred to as extrinsic allergic alveolitis, is characterized by non-IgE-mediated inflammation of the parenchyma, alveoli, and terminal airways of the lung initiated by inhaled antigens in a susceptible host. Etiologic agents of HP are either organic high molecular weight compounds such as bacteria, fungi, amoebae, plant, and animal proteins or inorganic low molecular weight haptens such as isocyanate and drugs including amiodarone, nitrofurantoin, and minocycline. Six significant predictors have been identified that provide ∼95% diagnostic accuracy. These six predictors are (1) exposure to a known offending allergen, (2) positive precipitating antibodies to the offending antigen, (3) recurrent episodes of symptoms, (4) inspiratory crackles on lung auscultation, (5) symptoms occurring 4-8 hours after exposure, and (6) weight loss. HP is staged into acute, subacute, and chronic. In the acute stage after direct exposure to the antigen, there is fever, chills, nonproductive cough, dyspnea, malaise, and myalgias, all resembling influenza. However, if obtained, a chest radiograph shows nodular infiltrates, and pulmonary function testing is restrictive (unless the cause is avian in which obstruction or obstruction with restriction is present). In the chronic stage, fever and chills are absent, but weight loss can occur. The immunologic response includes activated macrophages and CD8(+) cytotoxic lymphocytes, and bronchoalveolar lavage fluid reveals marked lymphocytosis with a ratio of CD4(+) cells to CD8(+) cells <1. Activated macrophages have increased expression of CD80/CD86, and T cells have increased expression of its counter-ligand CD28, evidence for heightened antigen presentation.

[Case of pneumonitis caused by Yokukansan]

A 74-year-old man was admitted to our hospital complaining of severe neck pain and general fatigue. He had been undergoing treatment for post-operative neck pain at the out-patient clinic of our hospital, but was now complaining of pain more intense than usual. Chest X-rays revealed diffuse ground glass shadows in bilateral lung fields, and computed tomography revealed diffuse intestinal shadows. A drug lymphocyte stimulation test (DLST) was also performed at that time. Steroid pulse therapy improved the clinical symptoms, hypoxemia and chest X-ray findings. DLST performed again with Yokukansan and Hachimijiogan 133 days after the initial diagnosis of pneumonitis showed Yokukansan was positive. This result showed Yukukansan may be a causative drug for allergic drug-induced pneumonitis. Any drugs including kanpo may be possible to induce allergic pneumonitis.

Respiratory health effects of large animal farming environments

With increases in large animal-feeding operations to meet consumer demand, adverse upper and lower respiratory health effects in exposed agriculture workers are a concern. The aim of this study was to review large animal confinement feeding operational exposures associated with respiratory disease with a focus on recent advances in the knowledge of causative factors and cellular and immunological mechanisms. A PubMed search was conducted with the keywords airway, farm, swine, dairy, horse, cattle inflammation, organic dust, endotoxin, and peptidoglycan, among items were published between 1980 and now. Articles were selected based on their relevance to environmental exposure and reference to airway diseases. Airway diseases included rhinitis, sinusitis, mucus membrane inflammation syndrome, asthma, chronic bronchitis, chronic obstructive pulmonary disease, hypersensitivity pneumonitis, and organic dust toxic syndrome. There is lower prevalence of immunoglobulin (Ig) E-mediated asthma and atopy in farmers and their children, but organic dust worsens existing asthma. Multiple etiologic factors are linked to disease, including allergens, organic dusts, endotoxins, peptidoglycans, and gases. Large animal confinement feeding operations contain a wide diversity of microbes with increasing focus on gram-positive bacteria and archaebacteria as opposed to gram-negative bacteria in mediating disease. Toll-like receptors (TLR) and nucleotide oligomerization domain (NOD)-like innate immune pathways respond to these exposures. Finally, a chronic inflammatory adaptation, tolerance-like response in chronically exposed workers occurs. Large animal confinement farming exposures produce a wide spectrum of upper and lower respiratory tract diseases due to the complex diversity of organic dust, particulates, microbial cell wall components, and gases and resultant activation of various innate immune receptor signaling pathways.

Hypersensitivity pneumonitis due to residential mosquito-coil smoke exposure

We reported a previously healthy 25-year-old female patient who developed hypersensitivity pneumonitis following repeated exposures to the smoke of mosquito coils. The patient presented with vague symptoms of cough and fever for 3 days. Diagnostic criteria proposed for clinical use in this case included history, exposure to a recognized antigen, physical examination, consistent radiographic images, bronchoalveolar lavage and lung biopsy. Much symptomatic relief and better radiographic response were noted after short-term use of oral corticosteroid and removal of the offending antigen.

[A case of acute hypersensitivity pneumonia in a worker at a feather duvet factory]

A 44-year-old woman was admitted to our hospital because of a 15-month history of exertional dyspnea, nonproductive cough and fever. Thoracic high-resolution computed tomography (HRCT) showed centrilobular ground-glass opacities distributed in bilateral lung fields. She had worked at a down quilt factory and had been exposed to a large amount of feathers for 5 years. A peripheral lymphocyte proliferation test by positive was positive for pigeon serum. We diagnosed bird-related hypersensitivity pneumonia. After quitting her job, improvement of her clinical symptoms and chest imaging findings were observed and she has been free of relapse.

[Chronic and acute hypersensitivity pneumonitis in a dairy farmer and his son]

We encountered a dairy farmer and his son with farmer's lung who had worked on the same farm for 25 years and 5 years, respectively. The son was admitted to our hospital because of cough, sputum, and shortness of breath. Chest computed tomography (CT) on admission revealed diffuse ground-glass opacities in both lung fields. Following admission, the clinical symptoms and radiological findings improved spontaneously without specific treatment. A provocation test (following return to work on the farm) elicited recurrence of the symptoms and radiological findings. He was diagnosed with acute hypersensitivity pneumonitis (HP) based on the clinical findings. After quitting his job, no reccurence was noted. The farther was admitted to our hospital complaining of repeated episodes of cough and high fever. He had been diagnosed with lung fibrosis 10 years previously. Chest CT on admission revealed progression of thin-walled cystic changes over ten years. Following admission, his symptoms improved without medication. However, because he has continued working on the farm, his radiological findings have gradually deteriorated. He was diagnosed with chronic HP based on his clinical features. These cases are suggestive of farmer's lung with familial occurrence, difference between acute HP and chronic HP, and long-term prognosis.

[A patient with acute hypersensitivity pneumonitis with a diagnosis of air-conditioner lung, who responded to therapy]

The patient was a 48-year-old woman and current smoker. In May 2007, she moved to a new residence. In the middle of the following month, she developed acute respiratory distress and a fever (38 degrees C) after running her air conditioner continuously throughout the night. The chest X-ray film showed diffuse infiltrative shadows in the middle and lower lung fields. After hospital admission, her oxygenation improved without treatment and the infiltrates improved over the clinical course. As a consequence, we suspected hypersensitivity pneumonitis. The bronchoalveolar lavage showed predominant lymphocytes of 72.6%, with a low CD 4/8 ratio of 0.2. Transbronchial lung biopsy findings corresponded to acute hypersensitivity pneumonitis. The results of the environmental challenge test were positive only when her air conditioner was on, resulting, in a diagnosis of air-conditioner lung. Several microorganisms were detected in an environmental sample, but 20 kinds of serum precipitating antibodies were negative on a thorough screening, so no responsible antigen could be identified. The patient's symptoms did not recur after her air conditioner was replaced.

[Modifications of the cytoimmunological pattern of bronchoalveolar lavage (BAL) material caused by cigarette smoking in selected lower air-way diseases]

INTRODUCTION

In the last years we have used flow cytometry as an auxiliary diagnostic tool in alveolar lymphocyte (i.e. originating from BAL) phenotyping in more than 500 persons suspected for lower airways pathology.

MATERIAL AND METHODS

In the study we compared the results of 1) BAL lymphocyte typing by flow cytometry, 2) cytological examination, respectively, in nonsmoking/smoking (NS/S) patients with lung sarcoidosis, n = 56/31, extrinsic allergic alveolitis (EAA), n = 9/5, silicosis, n = 15/18, idiopathic pulmonary fibrosis (IPF), n = 20/7, and pulmonary tuberculosis (TBC), n = 7/6. The results were related to the volume of BAL fluid recovery (higher value reflects the dominance of lower airways content versus bronchial content).

RESULTS

In smoking patients, in comparison with respective NS, significantly higher total BAL cell numer (except TBC), higher macrophage percentage, lower lymphocyte percentage and lower CD4/CD8 ratio (except EAA) was found. CD4/CD8 results: 8.26 +/- 0.52 (NS) vs 4.29 +/- 0.65 (S) in sarcoidosis (p < 0.001), 1.18 +/- 0.44 (NS) vs 0.99 +/- 0.43 (S) in IPF (p < 0.05), 1.79 +/- 0.22 (NS) vs 0.73 +/- 0.11 (S) in silicosis (p < 0.001) and 1.64 +/- 0.57 vs 0.88 +/- 0.1 in TBC (p < 0.05). Additionally, cigarette smoking modified BAL pattern: 1. in sarcoidosis and silicosis lower CD4+ cell and higher CD8+ cell percentage; 2. in IPF increase in neutrophil percentage; 3. in TBC higher neutrophil and eosinophil percentage. Both in NS and S, BAL fluid recovery rate is significantly positively correlated with CD4/CD8 ratio and total BAL CD3+ cell number and negatively with BAL CD8+ cell percentage.

CONCLUSIONS

Interpreting of BAL material cytoimmunology pattern should take into account data on cigarette smoking and BAL fluid recovery rate. The results obtained in the study may reflect more severe disease course in IPF and TBC.