Asthma Research Paper

Bronchial asthma

Asthma is one of the most common chronic medical diseases of childhood universally, affecting over 25 million people in the United States and 300 million people worldwide, with expectancy for that number to rise [1]. Compound measures to define asthma are necessary to obtain more accurate epidemiological prevalence estimates [2], and population-based studies are important for the assessment of these estimates [3].

Asthma is described as a chronic inflammatory condition of the airways consisting of a cellular component leading to airway inflammation, and smooth muscle hyper responsiveness in response to direct or indirect stimuli resulting in bronchoconstriction. Previous studies suggested that asthma is a multifactorial disease

Indirect stimuli, such as that of exercise, resulting in the release of inflammatory mediators from cells present in the airway contribute to airflow obstruction [5]. The Global Initiative for Asthma diagnostic criteria similarly are airway hyper responsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness, and coughing, particularly at night or in the early morning along with variable airflow obstruction which affect lung function [6].

In 1995, it was recommended that asthma “control” and “severity” should be differentiated. Severity is defined by the minimum medication needed to achieve proper asthma control rather than by symptoms or abnormal lung function. Thus, severe asthma is known as well controlled asthma symptoms on high to very high doses of inhaled corticosteroids, with or without the use of oral corticosteroids; and very severe asthma is defined as well or not well controlled asthma symptoms despite very high dose of inhaled and ingested corticosteroids and with or without additional therapies[7].

Refractory

These include corticosteroid-dependent asthma, glucocorticoid-resistant asthma, brittle or explosive asthma, and asthma with severe, irreversible airflow obstruction[45-47]. Patients with corticosteroid-dependent asthma are the most prevalent. Avery small subset of patients are truly corticosteroid resistant and do not benefit from continued administration of systemic corticosteroids [48].

Multiple variant approaches have been used to recognize phenotypes, including ‘phenotypes’ related to clinical characteristics (severity, fixed airflow limitation, age at onset), factors that associate with or induce asthma (allergic, aspirin, obesity) and lastly, pathobiological characteristics, including eosinophilic and neutrophilic inflammation[49]. Identification of heterogeneity and classification of asthma by phenotypes provides a foundation from which to understand disease etiology and to develop management approaches that lead to adequate asthma control while avoiding adverse effects and decreasing the risk of serious asthma outcomes (e.g., exacerbations and loss of pulmonary function