Chapter 11: Cough Assessment & Differential Diagnosis

Cough Assessment & Differential Diagnosis provides a comprehensive framework for the assessment and clinical diagnosis of cough in primary care, examining the symptom's pathophysiology as a reflex arc involving the vagus nerve and the medulla oblongata. The content categorizes coughs by duration into acute (less than 3 weeks), subacute (3 to 8 weeks), and chronic (more than 8 weeks) to streamline diagnostic reasoning, distinguishing between self-limiting viral infections and persistent pathologies like chronic obstructive pulmonary disease (COPD) or heart failure. It emphasizes the importance of a focused patient history to identify characteristics such as sputum production, odor, and color, which can indicate conditions ranging from anaerobic infections and bronchiectasis to allergic disorders. The text outlines critical physical examination techniques, including inspecting the chest for barrel shape and retractions, palpating for tactile fremitus, percussing for resonance or dullness, and auscultating for adventitious breath sounds like wheezes, crackles, and stridor. Diagnostic strategies are explored in depth, covering chest radiography, spirometry with methacholine challenge for asthma, esophageal pH monitoring for gastroesophageal reflux disease (GERD), and sweat chloride tests for cystic fibrosis. A significant portion of the chapter is dedicated to differential diagnoses, detailing the presentation and management of conditions such as Bordetella pertussis (whooping cough), croup (laryngotracheobronchitis), bronchiolitis caused by respiratory syncytial virus (RSV), bacterial and mycoplasma pneumonia, tuberculosis, and bronchogenic carcinoma. Additionally, the summary addresses non-infectious causes such as ACE inhibitor-induced cough, psychogenic habit coughs, and environmental triggers like cigarette smoke or occupational hazards.