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Biomedical subjects

O Vandenplas

Publications and source records attributed to O Vandenplas.

At least 37 records · Page 2Linked to original sources

Asthma and airway hyperresponsiveness among Belgian conscripts, 1978-91.

BACKGROUND: Although there is convincing evidence that the prevalence of asthma among children has increased over the last three decades, it remains uncertain whether such an upward trend has occurred in adults. The aim of this study was to assess whether the prevalence of asthma has changed in young Belgian adults in recent years. METHODS: A retrospective analysis was conducted of available statistics from the Belgian Armed Forces for the period 1978-91 because conscripts who reported a history of past or current asthma at call-up examination underwent standardised assessment of non-specific airway responsiveness by military chest physicians. Exemption from military service due to asthma was strictly based on the objective evidence of airway hyperresponsiveness. RESULTS: A mean of 48,331 conscripts aged 17-31 years were examined annually from 1978 to 1991. The prevalence of reported asthma rose from 2.4% in 1978 to 7.2% in 1991, while the proportion of asthmatics with airway hyperresponsiveness remained little changed at 48.4% in 1978 and 51.4% in 1991. CONCLUSIONS: The observed increase in prevalence of reported asthma was not accompanied by a decrease in the proportion of conscripts with objectively measured airway hyperresponsiveness. These observations provide supporting evidence that the increase in asthma symptoms was not simply due to reporting bias.

Adolescent↗

Granulomatous bronchiolitis associated with Crohn's disease.

Symptomatic bronchopulmonary disorders have been only occasionally reported in Crohn's disease, although several studies have documented the possibility of latent involvement of the respiratory tract. We report the case of a patient with long-standing Crohn's disease who presented with acute transient chest pain and a recent history of mild dyspnea and nonproductive cough. Chest radiographs were normal, while high-resolution computed tomography demonstrated a mosaic pattern of attenuation that was consistent with a bronchiolar disorder. Pulmonary function tests showed mild airway obstruction and normal diffusion indices. Thoracoscopic lung biopsy demonstrated focal infiltration of the bronchiolar walls by mononuclear cells and non-necrotizing granulomas. To our knowledge, this is the first account of isolated granulomatous bronchiolitis in Crohn's disease. These findings suggest that a granulomatous inflammatory process of the bronchioles could be involved in the development of airway obstruction in patients with Crohn's disease.

Adult↗

Occupational asthma caused by aluminium welding.

Work-related asthma has been documented in workers employed in the primary aluminium industry and in the production of aluminium salts. The role of aluminium in the development of occupational asthma has, however, never been convincingly substantiated. We investigated a subject who experienced asthmatic reactions related to manual metal arc welding on aluminium. Challenge exposure to aluminium welding with flux-coated electrodes, as well as with electrodes without flux, elicited marked asthmatic reactions. Manual metal arc welding on mild steel did not cause significant bronchial response. The results of inhalation challenges combined with exposure assessments provided evidence that aluminium can cause asthmatic reactions in the absence of fluorides. Awareness of this possibility may be relevant to the investigation of asthma in workers exposed to aluminium.

Adult↗

Metal fume fever.

Metal fume fever (MFF) is an acute self-limited, flu-like illness resulting from inhalation of metal oxides. Despite the well-documented history of MFF in the medical literature, the illness may remain unrecognized because it may mimic a viral illness. The case of a patient with MFF due to galvanized steel welding presenting to the emergency room is described.

Adult↗

Inhalation challenges with agents causing occupational asthma.

Occupational asthma (OA) is steadily emerging as the principal cause of respiratory disease due to the workplace environment. One of the key means to ascertain diagnosis of OA is specific inhalation challenge (SIC) with occupational agents. This review: 1) describes the methodology of SIC, with a special emphasis on procedures aimed at increasing the safety and validity of these tests; and 2) outlines the roles of SIC in the diagnosis of OA in clinical and medicolegal assessment, epidemiological studies, surveillance programmes and the investigation of the pathophysiological mechanisms of asthma and OA. We discuss areas of future development, including the development of apparatus which allows exposure of subjects to low and stable concentrations of the occupational agent and the assessment of preventive procedures.

Allergens↗

Increase in non-specific bronchial hyperresponsiveness as an early marker of bronchial response to occupational agents during specific inhalation challenges.

BACKGROUND: Specific bronchial reactivity to occupational agents may decline after exposure in the workplace ceases leading to falsely negative specific inhalation challenges. A study was carried out to assess prospectively whether increases in nonspecific bronchial hyperresponsiveness could be useful in detecting the bronchial response to occupational agents during specific inhalation challenges. METHODS: Specific inhalation challenges were performed in 66 subjects with possible occupational asthma due to various agents. After a control day the subjects were challenged with the suspected agent for up to two hours on the first test day. Those subjects who did not show an asthmatic reaction were rechallenged on the next day for 2-3 hours. The provocative concentration of histamine causing a 20% fall (PC20) in the forced expiratory volume in one second (FEV1) was assessed at the end of the control day as well as six hours after each challenge that did not cause a > or = 20% fall in FEV1. The subjects who had a significant (> or = 3.1-fold) reduction in PC20 value at the end of the second challenge day were requested to perform additional specific inhalation challenges. RESULTS: The first test day elicited an asthmatic reaction in 25 subjects. Of the other 41 subjects five (12%, 95% confidence interval (CI) 4% to 26%) exhibited a > or = 3.1-fold fall in the PC20 value after the inhalation challenge and developed an asthmatic reaction during the second (n = 3) or third (n = 2) challenge exposure. The offending agents included persulphate (n = 1), wood dust (n = 2), isocyanate (n = 1), or amoxycillin (n = 1). These five subjects had left their workplace for a longer period (mean (SD) 21 (14) months) than those who reacted after the first specific inhalation challenge (8 (11) months). CONCLUSIONS: The increase in non-specific bronchial hyperresponsiveness after a specific inhalation challenge can be an early and sensitive marker of bronchial response to occupational agents, especially in subjects removed from workplace exposure for a long time. Non-specific bronchial hyperresponsiveness should be systematically assessed after specific inhalation challenges in the absence of changes in airway calibre.

Adult↗

Occupational asthma due to gas metal arc welding on mild steel.

Occupational asthma has been documented in electric arc welders exposed to manual metal arc welding on stainless steel. A subject is described who developed late and dual asthmatic reactions after occupational-type challenge exposure to gas metal arc welding on uncoated mild steel.

Adult↗

Prevalence of occupational asthma due to latex among hospital personnel.

Latex has been documented as causing immediate hypersensitivity reactions ranging from contact urticaria to severe anaphylaxis. Latex proteins may also act as airborne allergens causing rhinitis and asthma. The prevalence of occupational asthma due to latex gloves among health care workers is unknown. We surveyed the employees of a primary care hospital including nurses (n = 201), members of the cleaning staff (n = 50), and laboratory technologists (n = 38). In the initial part of the study, a questionnaire and skin-prick tests with latex and common inhalant allergens were administered to 273 of 289 (94%) members of the target population. Thirteen of the 273 subjects (4.7%; 95% CI: 2.6 to 8.1%) showed skin reactivity to latex. All latex-sensitive subjects reported glove-related urticaria, which was associated with rhinoconjunctivitis in 12 subjects and asthma in five subjects. No subject had a history suggestive of occupational asthma among those who had negative skin tests to latex. In the second part of the study, a histamine inhalation challenge was performed on 12 of 13 latex-sensitive subjects, including the five subjects with a history of occupational asthma. These 12 subjects demonstrated significant bronchial hyperresponsiveness. All underwent specific inhalation challenges with latex gloves in the laboratory. Seven subjects developed a significant bronchial response (four immediate and three dual reactions) to latex glove exposure. We conclude that occupational asthma due to latex occurred in 2.5% (95% CI: 1.0 to 5.2%) of hospital employees. Widespread use of latex gloves should therefore be considered a significant risk to the respiratory health of hospital employees.

Adult↗

Latex gloves with a lower protein content reduce bronchial reactions in subjects with occupational asthma caused by latex.

Latex gloves have been documented as causing rhinitis and asthma. Using inhalation challenges, we evaluated the bronchial response to hypoallergenic gloves in eight health care workers with latex-induced asthma. The subjects were exposed to the powdered latex gloves causing asthma at work and various brands of gloves with a lower protein content, either low-powdered, nonpowdered, or powdered. Exposure to hypoallergenic gloves resulted in the absence (in six subjects) or a significant reduction (in two subjects) of bronchial response. The effects of repeated exposure to hypoallergenic gloves was assessed in two subjects who did not demonstrate changes in peak expiratory flow rates and nonspecific bronchial responsiveness to histamine. This study on a limited number of patients suggests that the use of hypoallergenic gloves could be an effective means of reducing the risk of asthmatic reactions in health care workers with latex-induced asthma when complete avoidance cannot be achieved. The long-term effect of exposure as well as the widespread use of hypoallergenic gloves warrant further investigation on larger cohorts of subjects.

Adult↗

Occupational asthma caused by natural rubber latex.

IgE-mediated sensitization in protein allergens of natural rubber latex (NRL) can induce immediate hypersensitivity reactions ranging from mild urticaria in life threatening anaphylaxis after cutaneous, mucosal or visceral exposure. Elutable allergens from NRL gloves absorb to the cornstarch powder particles, become airborne, and have the potential to cause respiratory reactions. Recent studies indicate that asthma is a frequent manifestation of NRL allergy among workers manufacturing NRL materials and among health-care providers using NRL workers. NRL-induced asthma should receive increasing attention as it can lead to permanent respiratory sequelae and occupational disability. The need for early and accurate diagnosis is outlined and the different diagnostic approaches are reviewed. Specific issues pertaining to the management of affected subjects and to the prevention of exposure to airborne NRL are discussed. Ares of future research should include: 1) further characterization of relevant NRL allergens; 2) development and validation of methods for quantitative assessment of allergen content in NRL devices and workplace environment; 3) evaluation of the natural history and risk factors of NRL-induced asthma; and 5) analysis of effectiveness and cost of preventive strategies.

Allergens↗

Occupational asthma caused by oak wood dust.

Three cases of occupational asthma caused by oak wood dust are presented. The diagnosis was confirmed by specific inhalation challenges, which induced a dual asthmatic reaction in two subjects and an atypical prolonged immediate reaction in one subject.

Adult↗

Allergenic exposure, IgE-mediated sensitization, and related symptoms in lawn cutters.

AIMS: The aims of the study conducted on lawn cutters were: (1) to evaluate exposure to pollens and molds; and (2) to assess the prevalence rate of IgE sensitization and symptoms in relation to exposure to pollens and molds. METHODS: Environmental assessment was done with the use of personal samplers on eight workers. Our population consisted of 181 municipal park workers, including 128 lawn cutters and 67 control subjects (blue-collar workers in the hospital). A questionnaire was administered, as well as skin prick tests with seven common inhalants including pollens and eight grass molds. The main outcome variables were grass or mold sensitization (at least one of eight molds) and work-related rhinitis, conjunctivitis, and rhinoconjunctivitis. Atopy and exposure to park-related allergens, as well as sensitization to grass pollens, were considered as explanatory factors. Smoking was taken into consideration as a covariant. Both presence and duration of occupational exposure to park-related allergens were considered as parameters of exposure. Duration of exposure (months x years of exposure as lawn cutters) was used as a continuous or as a categorical variable. RESULTS: Environmental monitoring showed that the concentration of pollens and molds decreased in magnitude from samples collected close to lawn cutters faces, short distance away in parks, and in the general environment. There was no difference in the prevalence rates for atopy between lawn cutters (32%) and control subjects (37%). Sensitization rates to grass pollen were also similar in lawn cutters (18%) and in control subjects (22%). However, there was a tendency for prevalence rates of sensitization to molds to be greater among lawn cutters (12% to Alternaria) compared with control subjects (5%). In the logistic model atopy was significantly related to grass sensitization (odds ratio [OR] = 7.2), mold sensitization (OR = 9.3), and sensitization to Alternaria (OR = 5.8). Grass sensitization was a significant risk factor for park-related rhinitis (OR = 5.8), conjunctivitis (OR = 5.0), and rhinoconjunctivitis (OR = 9.4). Exposure for 12 years or more was associated with rhinoconjunctivitis with an OR of 4.1 (95% confidence interval, 1.0-16.7). Smoking was not significantly related to any outcome. CONCLUSION: We conclude that among lawn cutters exposure to pollens and molds is higher than in the general population, atopy is the main determinant of sensitization to these aeroallergens, and sensitization and, to a much lesser extent, exposure to grass are determinants of symptoms.

Adult↗

Respiratory and systemic reaction following exposure to heated electrostatic polyester paint.

A 39 year old nonatopic man developed episodes of cough, dyspnoea, sweating and shivers within 2-3 weeks of starting a new job in a factory where metallic boards were treated with an electrostatic powder paint, made of an epoxy resin and a carboxylated polyester containing polyethylene terephthalate and polybutylene terephthalate. The subject sprayed the metallic boards which were then heated in 200 degrees C ovens. The subject was first seen in an emergency room after being at work for 4 h. The physical examination revealed bilateral wheezing with fever (39 degrees C), hypoxaemia (arterial oxygen tension (PaO2) 58 torr (7.7 kPa), leucocytosis (white blood count cells.mm-3 17,000 (17 x 10(9) cells.l-1) and severe airway obstruction (forced expiratory volume in one second (FEV1)/forced vital capacity, (FVC) 1.3/2.4 l, improving to 2.2/3.8 l after bronchodilator; predicted values = 3.4/4.1 l). The subjects condition improved after being treated with oral steroids. His spirometry was normal two weeks later, although he showed mild bronchial hyperresponsiveness to methacholine with the (provocative concentration producing a 20% fall in FEV1 (PC20) being 1.7 mg.ml-1). The subject underwent specific inhalation challenges at the workplace 4 months later. After being exposed at work for 4 h, he developed a significant fall in FEV1 (-40%), fever, leucocytosis, and a fall in diffusing capacity. Lung function tests were back to normal two weeks later. Exposing the subject to heated granulated polyester for one hour in a hospital laboratory produced a fall in FEV1 of 41%, fever, leucocytosis and a fall in diffusing capacity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗