Narrative Review: how long should patients with cough variant asthma or non-asthmatic eosinophilic bronchitis be treated?

Abstract

The causes of chronic cough can be categorized into eosinophilic and noneosinophilic disorders, and approximately 30% to 50% of people with chronic cough have eosinophilic airway inflammation, the presence of which can be confirmed by sputum eosinophilia or elevated exhaled nitric-oxide levels. Cough variant asthma (CVA) is a phenotype of asthma which lacks wheezing or dyspnea, and consistently one of the most common causes of chronic cough worldwide. CVA and non-asthmatic eosinophilic bronchitis (NAEB) shares common feature such as chronic dry cough, eosinophilic inflammation, and development of chronic airflow obstruction (CAO) and asthma in a subset of patients. The distinctive characteristic of these conditions is the presence of airway hyperresponsiveness in CVA but not in NAEB. Coughing is responsive to bronchodilators such as beta-agonists in CVA, but such feature has not been clarified in NAEB. Inhaled corticosteroids (ICSs) are the first-line treatment, and leukotriene receptor antagonists are also effective, in patients with both CVA and NAEB. This review will give an outline of clinical and physiological features, and prognosis and its determinants of CVA and EBNA. Further, the rationale and evidence, despite limited, for the need of long-term treatment will be discussed. The development of airway remodeling due to mechanical stress to the airways exerted by long-standing coughing will also be discussed.

Herb-CMap: Novel Hot Diffusion Algorithm to Identify Bioactive Ingredients from Herbal Medicine Based on Gene Perturbation Profiling

“…5A and C, Table S4). However, it was studied that the IL-17 signaling pathway was closely related to Th1 airway inflammation in asthma, while CVA was generally recognized as Th2 airway inflammation [45][46][47] . Therefore, we inferred that Suhuang may have other therapeutic effects on Th1 asthma (Fig.…”

Diagnosis and management of cough-variant asthma

“…Patients with cough-variant asthma who do not use inhaled corticosteroids have a progression rate to classic asthma of 30%-40% (3). Several factors that influence the progression of cough-variant asthma to classic asthma include airway hyperresponsiveness, excessive airway response to methacholine, sputum eosinophilia and sensitisation to allergens (21). The early use of inhaled corticosteroid therapy can reduce the risk of progression to classic asthma (3).…”

A smartphone-based application for cough counting in patients with acute asthma exacerbation

“…Cough is a normal defense mechanism of the human body and many diseases like respiratory infections, airway inflammatory diseases, and pulmonary malignancy present with cough as a primary symptom ( 1 ). In particular, cough is the most distressing symptom in patients with asthma during an acute exacerbation, and it is also the only symptom in cough variant asthma ( 2 ). Cough may precede dyspnea or wheezing in an acute asthma exacerbation, and evidence has been found that monitoring nocturnal coughs may detect asthma exacerbations earlier ( 3 , 4 ).…”