CMDT 2013
Common Symptoms Ralph Gonzales, MD, MSPH, & Paul L. Nadler, MD
COUGH
E ssent i al In q u i r i es Age. Duration of cough. Dyspnea (at rest or with exertion). Tobacco use history. Vital signs (heart rate, respiratory rate, body temperature). Chest examination. Chest radiography when unexplained cough lasts more than 3–6 weeks.
``General Considerations Cough adversely affects personal and work-related interactions, disrupts sleep, and often causes discomfort of the throat and chest wall. Most people seeking medical attention for acute cough desire symptom relief; few are worried about serious illness. Cough results from stimulation of mechanical or chemical afferent nerve receptors in the bronchial tree. Effective cough depends on an intact afferent–efferent reflex arc, adequate expiratory and chest wall muscle strength, and normal mucociliary production and clearance.
``Clinical Findings A. Symptoms Distinguishing acute (< 3 weeks), persistent (3–8 weeks), and chronic (> 8 weeks) cough illness syndromes is a useful first step in evaluation. Postinfectious cough lasting 3–8 weeks has also been referred to as subacute cough to distinguish this common, distinct clinical entity from acute and chronic cough. 1. Acute cough—In healthy adults, most acute cough syndromes are due to viral respiratory tract infections. Additional features of infection such as fever, nasal
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congestion, and sore throat help confirm the diagnosis. Dyspnea (at rest or with exertion) may reflect a more serious condition, and further evaluation should include assessment of oxygenation (pulse oximetry or arterial blood gas measurement), airflow (peak flow or spirometry), and pulmonary parenchymal disease (chest radiography). The timing and character of the cough have not been found to be very useful in establishing the cause of acute cough syndromes, although cough-variant asthma should be considered in adults with prominent nocturnal cough, and persistent cough with phlegm increases the patient’s likelihood of chronic obstructive pulmonary disease (COPD). The presence of post-tussive emesis or inspiratory whoop modestly increases the likelihood of pertussis, and the absence of paroxysmal cough decreases the likelihood of pertussis in adolescents and adults with cough lasting more than 1 week. Uncommon causes of acute cough should be suspected in those with heart disease (congestive heart failure [CHF]) or hay fever (allergic rhinitis) and those with environmental risk factors (such as farm workers). 2. Persistent and chronic cough—Cough due to acute respiratory tract infection resolves within 3 weeks in the vast majority of patients (over 90%). Pertussis infection should be considered in adolescents and adults who present with persistent or severe cough lasting more than 3 weeks. In selected geographic areas, the prevalence of pertussis approaches 20% when cough has persisted beyond 3 weeks, although the exact prevalence of pertussis is difficult to ascertain due to the limited sensitivity of diagnostic tests. When angiotensin-converting enzyme (ACE) inhibitor therapy, acute respiratory tract infection, and chest radiograph abnormalities are absent, the majority of cases of persistent and chronic cough are due to or exacerbated by postnasal drip, asthma, or gastroesophageal reflux disease (GERD). A history of nasal or sinus congestion, wheezing, or heartburn should direct subsequent evaluation and treatment, though these conditions frequently cause persistent cough in the absence of typical symptoms. Dyspnea at rest or with exertion is not commonly reported among patients with persistent cough. The report of dyspnea requires assessment for other evidence of chronic lung disease, CHF, or anemia. Bronchogenic carcinoma is suspected when cough is accompanied by unexplained weight loss and fevers with