摘要
Asthma is one of the most common chronic inflammatory diseases, affecting about 300 millionpeople worldwide and is estimated to account for about one of every 250 deaths and 15 million disability-adjusted life years lost annually.1 Most patients with asthma are easily diagnosed and respond to standard treatment with a short-acting inhaled 132-agonist for symptom control and long-term treatment with an inhaled corticosteroid （ICS） in doses of up to 2000 pg daily. On the other hand, despite treatment with high-dose therapy, approximately 5% of adult patients remain difficult to control, with persisting symptoms and frequent exacerbations. ＂Difficult asthma＂ may be defined as failure to control symptoms when maximally recommended doses of inhaled therapy are prescribed. This subgroup of patients is a cause for concern because of the potential consequences of uncontrolled disease, including fatal or near fatal asthma.
Asthma is one of the most common chronic inflammatory diseases, affecting about 300 millionpeople worldwide and is estimated to account for about one of every 250 deaths and 15 million disability-adjusted life years lost annually.1 Most patients with asthma are easily diagnosed and respond to standard treatment with a short-acting inhaled 132-agonist for symptom control and long-term treatment with an inhaled corticosteroid （ICS） in doses of up to 2000 pg daily. On the other hand, despite treatment with high-dose therapy, approximately 5% of adult patients remain difficult to control, with persisting symptoms and frequent exacerbations. ＂Difficult asthma＂ may be defined as failure to control symptoms when maximally recommended doses of inhaled therapy are prescribed. This subgroup of patients is a cause for concern because of the potential consequences of uncontrolled disease, including fatal or near fatal asthma.
