What is reactive airway disease, also known as asthma (Chronic Obstructive Pulmonary Disease, COPD)?

From the Guidelines

Reactive airway disease is a general term used to describe symptoms of wheezing, coughing, and shortness of breath caused by airway inflammation and constriction, often in response to certain triggers, as described in the guidelines for the diagnosis and management of asthma 1. It's not a specific diagnosis but rather a descriptive term commonly used when asthma hasn't been definitively diagnosed, especially in young children. The condition involves hypersensitive airways that narrow or tighten when exposed to irritants like smoke, dust, strong odors, cold air, respiratory infections, or allergens. This narrowing makes breathing difficult and produces symptoms similar to asthma. Some key points to consider include:

• The difference between reactive airway disease and asthma is primarily one of diagnostic certainty - reactive airway disease may be a temporary condition following a respiratory infection or may eventually be diagnosed as asthma if symptoms persist or recur.
• Treatment typically includes bronchodilators like albuterol to relax airway muscles, and sometimes inhaled corticosteroids like fluticasone to reduce inflammation, as recommended by the expert panel report 3 (EPR-3) 1.
• For acute episodes, a short course of oral steroids like prednisone may be prescribed.
• Avoiding triggers is essential for management.
• The pathophysiology of asthma, which is closely related to reactive airway disease, involves a complex disorder characterized by variable and recurring symptoms, airflow obstruction, bronchial hyperresponsiveness, and an underlying inflammation, as described in the guidelines for the diagnosis and management of asthma 1.
• Recent studies provide insights on different phenotypes of asthma that exist, which may have specific and varying patterns of inflammation, as noted in the expert panel report 3 (EPR-3) 1.
• The clinical diagnosis of COPD, which can be related to reactive airway disease, is suggested by symptoms, but can only be established firmly by an objective measurement indicating airflow obstruction, as described in the BTS guidelines for the management of chronic obstructive pulmonary disease 1.
• The differentiation of severe COPD from chronic severe asthma is difficult, as some degree of improvement in FEV1 (reversibility) can often be produced by bronchodilator therapy, as noted in the BTS guidelines for the management of chronic obstructive pulmonary disease 1.

From the FDA Drug Label

Inflammation is an important component in the pathogenesis of asthma. The effects of corticosteroids in the treatment of COPD are not well defined and ICS and fluticasone propionate when used apart from Wixela Inhub® are not indicated for the treatment of COPD.

Reactive Airway Disease is not explicitly defined in the provided drug label. However, based on the information provided, it can be inferred that asthma is a type of reactive airway disease, characterized by inflammation and bronchial hyper-responsiveness.

• Asthma is mentioned as a condition where inflammation plays a crucial role in its pathogenesis.
• Corticosteroids, such as fluticasone propionate, have anti-inflammatory effects that contribute to their efficacy in asthma.
• Salmeterol, a LABA, has bronchodilatory effects that help relax bronchial smooth muscle and inhibit the release of mediators of immediate hypersensitivity. 2

From the Research

Definition of Reactive Airway Disease

• Reactive airway disease is defined as the sudden onset of asthma following a high level exposure to a corrosive gas, vapor, or fume 3.
• It is a variant of occupational asthma that continues to generate controversy regarding the criteria for its diagnosis.

Characteristics of Reactive Airway Disease

• The diagnosis requires the assumption of normal premorbid pulmonary physiology and absence of bronchial hyperreactivity 3.
• The pathology of reactive airway disease involves a primarily lymphocytic inflammatory response with some evidence of subepithelial thickening and fibrosis 3.
• Most patients with this condition who survive the short-term exposure to a toxicant recover completely without significant clinical or physiologic sequelae 3.

Distinction from Other Respiratory Conditions

• Reactive airway disease is distinct from chronic obstructive pulmonary disease (COPD), which is a global public health problem with increasing impact 4, 5.
• While COPD is characterized by a gradual decline in lung function, reactive airway disease is marked by a sudden onset of symptoms following exposure to a toxic substance 3.