Work-related asthma / Asma relacionada ao trabalho

ABSTRACT Work-related asthma (WRA) is highly prevalent in the adult population. WRA includes occupational asthma (OA), which is asthma caused by workplace exposures, and work-exacerbated asthma (WEA), also known as work-aggravated asthma, which is preexisting or concurrent asthma worsened by workplace conditions. In adults, the estimated prevalence of OA is 16.0%, whereas that of WEA is 21.5%. An increasing number of chemicals used in industrial production, households, and services are associated with the incidence of adult-onset asthma attributable to exposure to chemicals. This review article summarizes the different types of WRA and describes diagnostic procedures, treatment, prevention, and approaches to patient management. It is not always easy to distinguish between OA and WEA. It is important to establish a diagnosis (of sensitizer-/irritant-induced OA or WEA) in order to prevent worsening of symptoms, as well as to prevent other workers from being exposed, by providing early treatment and counseling on social security and work-related issues.

RESUMO A asma relacionada ao trabalho (ART) é um acometimento com elevada prevalência na população adulta. A ART inclui a asma ocupacional (AO), desencadeada pela exposição a um agente presente em um determinado ambiente de trabalho, e a asma agravada ou exacerbada pelo trabalho (AA/ET), que acomete indivíduos com antecedentes de asma ou que iniciaram um quadro de asma concomitante, mas sem relação causal com o ambiente de trabalho. Estima-se que 16,0% e 21,5% da asma no adulto sejam AO e AA/ET, respectivamente. O elevado e crescente número de substâncias químicas usadas na produção industrial, no uso domiciliar ou em serviços é responsável pela incidência de asma associada à exposição a agentes químicos na vida adulta. Este artigo de revisão descreve os principais tipos de ART, os procedimentos para seu diagnóstico, tratamento e prevenção e as condutas frente ao diagnóstico. Nem sempre é fácil a distinção entre AO e AA/ET. A importância do diagnóstico (AO ou AA/ET e asma induzida por sensibilizantes ou irritantes) tem relação com a adoção de medidas de prevenção para evitar que novos indivíduos sejam expostos e que os acometidos apresentem agravamento da doença, utilizando tratamento precoce e fornecendo orientação sobre aspectos previdenciários e trabalhistas.

Update on the Management of Occupational Asthma and Work-Exacerbated Asthma

Work-related asthma is the most common occupational lung disease encountered in clinical practice. In adult asthmatics, work-relatedness can account for 15%–33% of cases, but delays in diagnosis remain common and lead to worse outcomes. Accurate diagnosis of asthma is the first step to managing occupational asthma, which can be sensitizer-induced or irritant-induced asthma. While latency has traditionally been recognized as a hallmark of sensitizer-induced asthma and rapid-onset a defining feature of irritant-induced asthma (as in Reactive Airway Dysfunction Syndrome), there is epidemiological evidence for irritant-induced asthma with latency from chronic moderate exposure. Diagnostic testing while the patient is still in the workplace significantly improves sensitivity. While specific inhalational challenges remain the gold-standard for the diagnosis of occupational asthma, they are not available outside of specialized centers. Commonly available tests including bronchoprovocation challenges and peak flow monitoring are important tools for practicing clinicians. Management of sensitizer-induced occupational asthma is notable for the central importance of removal from the causative agent: ideally, removal of the culprit agent; but if not feasible, this may require changes in the work process or ultimately, removal of the worker from the workplace. While workers' compensation programs may reduce income loss, these are not universal and there can be significant socio-economic impact from work-related asthma. Primary prevention remains the preferred method of reducing the burden of occupational asthma, which may include modification to work processes, better worker education and substitution of sensitizing agents from the workplace with safer compounds.

Doença alérgica ocupacional: aspectos socioepidemiológicos em ambulatório especializado na cidade de São Paulo / Occupational allergic disease: socio-epidemiological aspects from a specialized outpatient clinic at the city of Sao Paulo

Introdução: Doença ocupacional envolvendo o sistema imunológico é considerada doença alérgica ocupacional (DAO). Das doenças ocupacionais, 15% são alérgicas. As consequências sociais do diagnóstico de DAO são importantes para o trabalhador e empregador. Objetivos: Descrever características demográficas e clínicas dos pacientes estudados com DAO e seus desfechos sociais. Métodos: Estudo descritivo, retrospectivo dos prontuários de pacientes do ambulatório de alergia ocupacional de hospital universitário em São Paulo, com diagnóstico de DAO. Resultados: 72 pacientes apresentaram DAO, com idades entre 21 e 89 anos; 52% do sexo masculino. Antecedentes atópicos foram descritos em 35% dos pacientes. A maioria dos pacientes trabalhava nas áreas de indústria química (17%), limpeza (15%), construção civil (11%) e saúde (8%). Rinite ocupacional foi vista em 26% dos pacientes; asma relacionada ao trabalho, em 18%; asma e rinite, em 25%; dermatite de contato alérgica, em 13%. Sobre o desfecho social, 36 (50%) mantiveram-se em seus cargos, 19 (26%) mudaram de função, 7 (10%) mudaram de área, 7 (10%) foram afastados e 3 (4%) se aposentaram. Conclusões: Na casuística estudada, a DAO prevaleceu no sexo masculino, em faixa etária condizente com faixa trabalhadora; com maior número de casos de rinite ocupacional. Metade dos pacientes continuou exercendo a mesma função mesmo após o diagnóstico.

Background: Occupational diseases involving the immune system are considered as occupational allergic diseases (OAD); 15% of occupational diseases are allergic. The social consequences of OAD are significant for both workers and employers. Objectives: To describe demographic and clinical characteristics of patients with OAD and their social outcomes. Methods: Descriptive and retrospective study of the medical records of patients diagnosed with OAD and cared at the occupational allergy clinic of a university hospital in São Paulo, Brazil. Results: A total of 72 patients exhibited OAD, with age from 21 to 89 years old; 52% were male. Atopic antecedents were described for 35% of patients. Most patients worked in the chemical industry (17%), cleaning (15%), construction (11%) and health (8%). Occupational rhinitis was found in 26% of the patients, work-related asthma in 18%, asthma and rhinitis in 25%, and allergic contact dermatitis in 13%. In regard to the social outcomes, 36 (50%) remained in their job, 19 (26%) changed function, 7 (10%) changed work area, 7 (10%) were fired and 3 (4%) retired. Conclusions: In the present study, OAD prevailed in males and the economically active age; cases of occupational rhinitis were the most frequent. Half of the employees remained in the same function even after diagnosis.

Enfermedades respiratorias ocupacionales / Occupational pulmonary diseases

Las enfermedades ocupacionales son aquellas producidas directamente por el ejercicio de la profesión. Estas se encuentran reguladas por la Ley 16.744 y son de cargo de prestadores de servicios denominados habitualmente mutuales. En este artículo se describen los principales aspectos epidemiológicos, fisiopatológicos, clínicos, de criterios diagnósticos y principios terapéuticos, de cuatro enfermedades respiratorias, las más relevantes en el medio nacional: Silicosis, asma, enfermedades por asbesto y enfermedades por hipobaria.

Occupational diseases are those produced directly by work activities. In Chile, occupational diseases are regulated by the law 16.744 and the service providers are called, mutualidades. In this paper is described epidemiology, physiopathology, clinical aspects, diagnostic criteria and therapeutic principles of the four most important occupational respiratory diseases in Chile: Silicosis, occupational asthma, asbestos diseases and altitude sickness.

Case Report of Occupational Asthma Induced by Polyvinyl Chloride and Nickel

Polyvinyl chloride (PVC) is a widely used chemical for production of plastics. However occupational asthma (OA) caused by PVC has been reported only rarely. We report a 34-yr-old male wallpaper factory worker with OA due to PVC and nickel (Ni) whose job was mixing PVC with plasticizers. He visited the emergency room due to an asthma attack with moderate airflow obstruction and markedly increased sputum eosinophil numbers. A methacholine challenge test was positive (PC20 2.5 mg/mL). Bronchoprovocation tests with both PVC and Ni showed early and late asthmatic responses, respectively. Moreover, the fractional concentration of exhaled nitric oxide (FeNO) was increased after challenge with PVC. To our knowledge, this is the first case of OA in Korea induced by exposure to both PVC and Ni. We suggest that eosinophilic inflammation may be involved in the pathogenesis of PVC-induced OA and that FeNO monitoring can be used for its diagnosis.

Role of vitamin D-binding protein in isocyanate-induced occupational asthma

The development of a serological marker for early diagnosis of isocyanate-induced occupational asthma (isocyanate-OA) may improve clinical outcome. Our previous proteomic study found that expression of vitamin D-binding protein (VDBP) was upregulated in the patients with isocyanate-OA. In the present study, we evaluated the clinical relevance of VDBP as a serological marker in screening for isocyanate-OA among exposed workers and its role in the pathogenesis of isocyanate-OA. Three study groups including 61 patients with isocyanate-OA (group I), 180 asymptomatic exposed controls (AECs, group II), 58 unexposed healthy controls (NCs, group III) were enrolled in this study. The baseline serum VDBP level was significantly higher in group I compared with groups II and III. The sensitivity and specificity for predicting the phenotype of isocyanate-OA with VDBP were 69% and 81%, respectively. The group I subjects with high VDBP (> or = 311 microg/ml) had significantly lower PC20 methacholine levels than did subjects with low VDBP. The in vitro studies showed that TDI suppressed the uptake of VDBP into RLE-6TN cells, which was mediated by the downregulation of megalin, an endocytic receptor of the 25-hydroxycholecalciferol-VDBP complex. Furthermore, toluene diisocyanate (TDI) increased VEGF production and secretion from this epithelial cells by suppression of 1,25-dihydroxycholecalciferol [1,25(OH)2D3] production. The findings of this study suggest that the serum VDBP level may be used as a serological marker for the detection of isocyanate-OA among workers exposed to isocyanate. The TDI-induced VEGF production/secretion was reversed by 1,25(OH)2D3 treatment, which may provide a potential therapeutic strategy for patients with isocyanate-OA.