Increasing evidence suggests that patients with asthma have activated coagulation within the airways. Whether this leads to an increase in venous thromboembolic events is unknown. We therefore assessed the incidence of venous thromboembolic events in patients with mild-to-moderate and severe asthma as compared with an age-and sex-matched reference population.648 patients with asthma (283 with severe and 365 patients with mild-to-moderate asthma) visiting three Dutch outpatient asthma clinics were studied. All patients completed a questionnaire about a diagnosis of deep vein thrombosis and pulmonary embolism in the past, their risk factors, history of asthma and medication use. All venous thromboembolic events were objectively verified.In total, 35 venous thromboembolic events (16 deep vein thrombosis and 19 pulmonary embolism) occurred at a median age of 39 (range 20-63) years. The incidence of pulmonary embolism in patients with severe asthma was 0.93 (95% CI 0.42-1.44) per 1000 person-years, 0.33 (95% CI 0.07-0.60) in mild-tomoderate asthma and 0.18 (95% CI 0.03-0.33) in the general population, respectively. Severe asthma and oral corticosteroid use were independent risk factors of pulmonary embolism (hazard ratios 3.33 (1.16-9.93) and 2.82 (1.09-7.30), respectively). Asthma was not associated with deep vein thrombosis.Severe asthma greatly enhances the risk of pulmonary embolism, particularly if chronic corticosteroids are used. @ERSpublications Severe asthma greatly enhances the risk of pulmonary embolism, particularly if chronic corticosteroids are used

The beneficial effects of high-altitude treatment in asthma have been attributed to allergen avoidance. Recent evidence shows that this treatment also improves airway inflammation in nonallergic patients. We hypothesised that high-altitude treatment is clinically equally effective in patients with severe refractory asthma, with or without allergic sensitisation.In a prospective observational cohort study, 137 adults with severe refractory asthma (92 with allergic sensitisation), referred for high-altitude (1,600 m) treatment in Davos, Switzerland, were consecutively included. We measured asthma control (Asthma Control Questionnaire (ACQ)), asthma-related quality of life (Asthma-Related Quality of Life Questionnaire (AQLQ)), sino-nasal symptoms (Sino-Nasal Outcome Test (SNOT-20)), medication requirement, postbronchodilator (post-BD) forced expiratory volume in 1 s (FEV1), 6-min walking distance (6MWD), total immunoglobulin (Ig)E, blood eosinophils and exhaled nitric oxide fraction (FeNO) at admission and after 12 weeks.Sensitised and nonsensitised patients showed similar improvements in ACQ (-1.4 and -1.5, respectively; p50.79), AQLQ (1.6 and 1.5, respectively; p50.94), SNOT-20 (-0.7 and -0.5, respectively; p50.18), post-BD FEV1 (6.1% and 5.8% pred, respectively; p50.87), 6MWD (+125 m and +147 m, respectively; p50.43) and oral steroids (40% versus 44%, respectively; p50.51). Sensitised patients showed a larger decrease in total IgE, blood eosinophils and FeNO.High-altitude treatment improves clinical and functional parameters, and decreases oral corticosteroid requirement in patients with severe refractory asthma, irrespective of allergic sensitisation.

Background: The use of anti-allergic mattress covers in patients with asthma can result in a large reduction in the level of house dust mite allergen in dust samples. Apart from a reduction in histamine induced bronchial hyperresponsiveness, there are few data on the effect of mattress covers on clinical efficacy and quality of life in patients with moderate to severe asthma. Methods: Thirty patients with asthma and house dust mite allergy were studied in a randomised, double blind, placebo controlled study. Before and after using anti-allergic covers for 1 year, dust was collected from the mattresses to determine concentrations of Dermatophagoides pteronyssinus (Der p 1), and bronchial hyperresponsiveness and quality of life were measured. The patients scored their symptoms (lungs and nose), morning and evening peak flow values, and rescue medication for 14 days before and after the intervention period.Results: There was a significant reduction in the concentration of Der p 1 in the dust collected from the mattresses in the actively treated group after 1 year compared with before treatment; no change was found in the placebo group. In both the actively treated and placebo groups there was no significant improvement in PC 20 histamine. Quality of life improved similarly in both groups. The symptom score of the lower airways did not significantly change in either group. A significant decrease in nasal symptom score was seen in the actively treated group compared with before treatment, but there was no significant difference between the groups. No changes in morning and evening peak flow values, peak flow variability, nor in the use of rescue medication were found in either group. Conclusion: The use of anti-allergic mattress covers results in significant reductions in Der p 1 concentrations in carpet-free bedrooms. However, in patients with moderate to severe asthma, airways hyperresponsiveness and clinical parameters are not affected by this effective allergen avoidance.

High-altitude treatment has been applied for more than a century in the treatment of pulmonary diseases including asthma. Many uncontrolled and controlled studies have shown its beneficial effects in children and adolescents with house dust mite allergic asthma. A recent study also showed an improvement in markers of airway inflammation in adult patients with severe intrinsic asthma, suggesting that factors other than HDM avoidance may contribute to the beneficial influence of the high-altitude climate therapy on asthma. The dry mountain climate not only has decreased levels of mite allergens but also decreased levels of pollens, fungal spores and air pollution, as well as high exposure to UV light with immunomodulatory and anti-inflammatory effects. Treatments targeting environmental control have never been investigated systematically in severe asthma, which is surprising, as environmental factors have been recognized as important contributors to asthma severity for many years and more evidence has been accumulating ever since. Preliminary evidence shows the beneficial effects of high-altitude treatment in patients with severe refractory asthma on symptoms, lung function and oral corticosteroid requirement, irrespective of atopic status. In this narrative review, we will discuss why high-altitude treatment might be a promising therapeutic option for patients who suffer from this disabling disease.

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