During the first years of life, airway infections commonly involve coughing, but the cough normally ceases within two to three weeks. 1-3 Some children experience recurrent episodes with cough or chronic cough, sometimes leading to the suspicion of an underlying disease. Chronic cough is defined as a cough that persists for more than four or eight weeks, 4-10 and in preschool children, the cough is mainly wet or productive due to mucus secretion. 4 An untreated chronic cough may last for months and lead to impaired sleeping, poor feeding, sick leave and reduced quality of life for the children and families affected. 4,5,7,10,11 Most children with recurrent episodic or chronic wet cough probably have a good prognosis, but for some children, the cough represents the first sign of chronic suppurative lung disease, which is important to diagnose and treat early. 5,10,12