Asthma

Key Statements 

• Asthma is a life-long chronic inflammatory disorder of the airways, associated with variable structural changes, that affects children and adults of all ages. It is associated with airway hyperresponsiveness and airflow obstruction that is often reversible either spontaneously or with treatment. 

• When uncontrolled, asthma can cause death, and can markedly interfere with normal activities, seriously impacting an individual’s quality of life. 

• Because of under-diagnosis and inadequate treatment, asthma presents a serious public health problem throughout the world, especially in low and middle income countries. 

• Atopy - the genetic predisposition to develop IgE-mediated sensitivity to common aeroallergens - is the strongest identifiable predisposing factor to the development of asthma, especially in children. 

• There was a sharp increase in the prevalence, morbidity, and mortality associated with asthma beginning in the 1960’s and 1970’s in the so-called “Westernized” countries of the world. 

• The prevalence of asthma in different countries varies widely, but the disparity is narrowing due to rising prevalence in low and middle income countries as they adopt a more Western-type lifestyle. It is plateauing in high income countries. 

• Inhaled corticosteroids are currently the most effective anti-inflammatory medications to treat persistent asthma. 

• The monetary costs of asthma are substantial and include both direct medical costs and the indirect costs, the latter associated with time lost from work and premature deaths. 

• National efforts to tackle asthma as a public health problem, such as the program introduced in Finland, produce remarkable benefits that are reflected in dramatic reductions in deaths and hospital admissions. 

• Many barriers exist to a reduction in the worldwide burden of asthma. 

• There are unmet diagnostic, therapeutic, educational and financial needs to achieve better worldwide control of asthma.

• More effort is needed to focus on ways to improve the management of asthma by focusing on disease control rather than treating acute episodes. This concept has to be embedded in healthcare programs.

Asthma Definitions and Characteristics 

Asthma is a chronic inflammatory disorder of the airways associated with airway hyperresponsiveness and airflow obstruction that is often reversible either spontaneously or with treatment. There is a strong genetic basis for the susceptibility to develop asthma, however, the impact of environmental factors predominates in determining the prevalence of asthma in a particular population. The genetic predisposition to develop IgE mediated sensitivity to common aeroallergens is the strongest identifiable predisposing factor for the development of asthma, especially in children. Other factors include exposure to environmental tobacco smoke, air pollution, early life respiratory viral infections, certain drugs, and stress. It is important to differentiate the asthmatic state of the airways in affected individuals that is caused by on-going chronic inflammation from acute exacerbations triggered by inadequate treatment and a wide range of environmental factors. 

Symptoms 

Patients with asthma typically experience recurrent episodes of wheezing, breathlessness, chest tightness and coughing, particularly at night or in the early morning. These symptoms are usually associated with airflow obstruction which is reversible spontaneously or following treatment. The patterns of these symptoms that strongly suggest an asthma diagnosis are variability, relationship to allergen exposures, precipitation by virus infection and non-specific irritants, such as smoke, outdoor air pollutants, fumes, strong smells or exercise, worsening at night, and responding to appropriate asthma therapy. Presence of a positive family history of asthma or other atopic diseases increases the likelihood that the symptoms are due to asthma, but asthma occurring later in life is often of the non-atopic form.