Asthma

Definition - A common chronic disorder of the airways that is complex and characterized by variable and recurring symptoms, airflow obstruction, bronchial hyperresponsiveness, and an underlying inflammation. The latter definition of asthma has features that overlap with the description of COPD. Besides historic features (such as the onset of disease in middle age/older, history of cigarette smoking), the characteristic that best distinguishes COPD from asthma is the degree of reversibility of airflow obstruction.

Clinical Features

•  Asthma is diagnosed before the age of seven years in approximately 75 percent of cases and may resolve when the patient begins puberty. Asthma may reoccur later in adulthood. 
• A pattern of respiratory symptoms that occur with exposure to triggers (such as a allergen, exercise, viral infection) and resolve with trigger avoidance or asthma medication is typical of asthma. 
• Patients often report 2 out of 3 of the following symptoms
• Wheezing
• Coughing (often worse at night)
• Shortness of Breath or difficulty breathing

Diagnosis - A history of intermittent symptoms typical of asthma plus the finding on physical examination of characteristic musical wheezing, when patient is symptomatic, strongly point to a diagnosis of asthma. Diagnosis is confirmed by evaluating the following...

• Pulmonary function test - will tell you if the lung disease is a obstructive pattern (FEV1/FVC < 0.7) and what the response after bronchodilator therapy
• Response to bronchodilator - The presence of a bronchodilator response, in isolation, is not enough to diagnose asthma. Asthma is typically distinguished from these other conditions (COPD, bronchiectasis, cystic fibrosis, and bronchiolitis) by the large response as at least 15 to 20 percent. 

Treatment - Once you have diagnosed Asthma, what are the goals of management and treatment options? The goals of chronic asthma management may be divided into two domains...

•  Reduction in impairment - Specific goals for reducing impairment include..
• Freedom from frequent or troublesome symptoms of asthma
• Minimal need (≤2 days per week) of inhaled short acting beta agonists to relieve symptoms
• Few night-time awakenings (<2 nights per month) due to asthma
• Oral glucocorticoid courses and/or urgent care visits should be needed no more than once per year
• Maintenance of normal daily activities, including work or school attendance and participation in athletics and exercise
• Satisfaction with asthma care on the part of patients and families
• Reduction in risk 
• Prevention of recurrent exacerbations and need for emergency department or hospital care
• Prevention of reduced lung growth in children, and loss of lung function in adults
• Optimization of pharmacotherapy with minimal or no adverse effects

Treatment - First, you want to categorize the patient's report of symptoms into a category (See figure below)

Once you have the patient's symptom categorized, you can chose a treatment plan. 

• Mild Intermittent - Patients with mild intermittent asthma are best treated with a quick-acting inhaled beta-2-selective adrenergic agonist, taken PRN for relief of symptoms.
• Mild Persistent - distinction between intermittent and mild persistent asthma is important, because current guidelines for mild persistent asthma call for initiation of daily long-term controller medication, a low dose inhaled glucocorticoid.
• Moderate Persistent - the preferred therapies are either low-doses of an inhaled glucocorticoid plus a long-acting inhaled beta agonist, or medium doses of an inhaled glucocorticoid
• Severe Persistent - medium or high doses of an inhaled glucocorticoid, in combination with a long-acting inhaled beta-agonist