Many times, chronic cough is difficult to resolve with any diagnostic tool, though less frequent than the viral induced recurrent cough.

Many authors have estimated that a cough can be considered a chronic cough after three weeks of duration. Few study papers have been published relating to etiologic diagnosis of chronic cough in childhood. However, these indicate the same main causes that are observed as in adults such as cough variant asthma, gastro-oesophageal reflux and postnasal drip syndrome. Yet, each age bracket represents specific diagnosis such as malformations between zero- and one-year and psychogenic cough in adolescents.

New techniques such as induced sputum studies are helping to refine chronic cough diagnosis in childhood particularly after 7 years. Eosinophilic bronchitis, associated or not related to bronchial hyperresponsiveness, has few important therapeutic consequences if associated with a favourable response to corticosteroids. Other techniques are going to be developed in the future.

Thus, it is concluded that chronic cough in childhood should be investigated from an anatomic point of view and on frequent influences. Control as well as elimination of the cough can only be obtained if a specific diagnosis with an appropriate treatment is achieved.

Source: Pradal M, Retornaz K, Poisson A. Toux chronique de lenfant [Chronic cough in childhood]. Rev Mal Respir. 2004 Sep;21(4 Pt 1):743-62. French. doi: 10.1016/s0761-8425(04)71416-3. PMID: 15536376; PMCID: PMC7135783.