Systematic Evaluation of Chronic Cough
Chronic cough can be differentiated from acute cough by an arbitrary cutoff
of 8 weeks (1). This distinction is helpful in clinical practice as the etiology and epidemiology of chronic cough are quite different from those of acute
cough. However, when faced with a chronic cough patient, determining
which of the possible underlying causes is to blame can be far from easy.
Community-based data on chronic cough reveal a suboptimally managed
population whose median duration of cough is 6.5 years, despite a high rate
of medical consultations in both primary and secondary care (2). In con-
trast, data from specialist cough clinics, where a more systematic approach
to diagnosis and management is usually employed, support very high treatment success rates (3). This is because cough may arise from anywhere
along the distribution of the vagus nerve and therefore the possibility of dis-
ease in a variety of different systems must be considered in a logical and
structured way. Indeed, one of the important reasons for misdiagnosis of
chronic cough in both primary and secondary care is the failure to consider
common extrapulmonary causes (4).