温州医科大学《内科学》section 4 AN APPROACH TO RESPIRATORY SYMPTOMS 18-21.PDFVIP

Section 4 AN APPROACH TO RESPIRATORY SYMPTOMS Chapter 18 Cough l Surinder S. Birring Ian D. Pavord COUGH IN HEALTH AND DISEASE normal findings on spirometry and chest radiography, the underlying cause is asthma, eosinophilic bronchitis, gastro- Cough is an important defense mechanism that clears the esophageal reflux, or rhinitis, or a combination of these. Many airways of secretions and prevents entry of foreign bodies and of these conditions can be recognized clinically, and successful irritants to the lower respiratory tract. It is a universal experi- diagnosis and management often are possible without recourse ence in health but also a nonspecific presenting feature of most to expensive or invasive investigations. respiratory conditions and a number of nonrespiratory condi- This chapter focuses primarily on isolated chronic cough, tions. Acute cough is one of the most common presenting because it is a common condition not dealt with elsewhere in symptoms in the patient population encountered by the general this book. In addition, an isolated chronic cough often is a dif- practitioner. In most cases, cough results from viral and bacte- ficult diagnostic problem for both primary and secondary care rial upper respiratory tract infection, is a self-limiting problem, physicians. This category of cough is thought to involve a and does not require further evaluation, but a small proportion primary abnormality of the cough reflex leading to a height- of patients will have persistent cough that necessitates special- ened response to known tussive stimuli. ist opinion. Chronic cough is arbitrarily defined as presence of cough fo