Chronic cough and wheeze in children: do they all have asthma?

In the experience of both authors, children referred for investigation of a chronic productive cough often do not fit conventional diagnostic categories. The aim of this study was to answer two questions: 1) do such diagnostic orphans exist? and, 2) if so, can they be classified in a clinically useful manner? Eighty one previously undiagnosed children referred with a history of more than 3 months productive or rattly cough were studied prospectively. Investigations consisted of a detailed history, physical examination, and an extensive set of clinical investigations. Sixty randomly selected asthmatic children served as demographic controls. Children fell into three groups: 23 had newly diagnosed conditions, such as cystic fibrosis, or were indistinguishable from asthma; 24 had a history of major medical interventions (cardiac surgery, chemotherapy, tracheo-oesophageal fistula repair); 34 had a history of significant early respiratory tract infections, usually combined with poor social conditions. The latter group differed significantly from asthmatic controls in a wide range of demographic and clinical comparisons. Native American children were overrepresented. The results of this study suggest that early respiratory insults (whether viral or medical) can induce self-perpetuating inflammation, manifesting as a chronic productive cough and intermittent wheeze. The associations between poverty and infant chest infections or early invasive medical treatment with subsequent chronic respiratory disease are clearly definable and probably justify diagnostic terms distinct from asthma, particularly for use in epidemiological studies.