Cough is one of the most significant defense mechanisms of the respiratory system. It contributes to the airway clearance from pathogens, microorganisms and secretions.

During a respiratory viral illness, systemic symptoms (fever, malaise, decrease appetite) last for approximately 3 days, whereas cough can persist up to 3 weeks in a great percentage of patients. Therefore, despite the fact, that cough creates an unpleasant feeling in children and is quite worrisome to parents, it is generally a protective mechanism that appears often in children of preschool age.

Chronic cough is the cough that lasts more than 4 weeks and it can be dry or wet (productive). The most common of chronic dry cough is asthma whereas chronic wet cough is commonly due to postnasal drip and protracted bacterial bronchitis. Less frequently, causes such as reflux, foreign body aspiration, immunodeficiencies, cystic fibrosis and primary ciliary dyskinesia can cause chronic wet cough but most of the times, the above conditions are associated with additional signs and symptoms.

A comprehensive medical history and a thorough physical exam set the ground for the diagnosis. Additionally, spirometry and chest radiograph can provide important information. However, in some cases, it is required to perform flexible bronchoscopy, computed tomography (CT) of the chest and specific blood tests.