Common misconceptions and mistakes
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Evaluating and treating a chronic purulent cough in the same fashion as a chronic dry cough
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Failing to obtain chest imaging in individuals complaining of a subacute and/or chronic cough
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Abandoning a diagnosis of the upper airway cough syndrome before maximally and simultaneously treating all of its components
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Prematurely diagnosing a chronic chough as psychogenic
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Believing that bronchoscopy is an important, early part of the evaluation of chronic cough
The Cough Reflex Arc
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A cough starts with the stimulation of irritant receptors located in the mucosa of the posterior oral pharynx, vocal cords, trachea, and airways
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Irritant receptors are activated by mechanical, thermal, chemical, and pH stress disturbance, such that the presence of any foreign material or fluid triggers a cough
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Afferent nerve impulses travel to the medulla, where efferent impulses are generated, producing a stereotyped sequence of events collectively known as a cough
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Inspiration, glottic closure, diaphragmatic relaxation, and forceful expiratory muscle contraction (raising intrapleural pressure transiently to 300 mm Hg) is followed by sudden glottic opening
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The explosive release of this high transpulmonary pressure gradient leads to high-velocity airflow, which is designed to expel foreign material from the airways
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Acute Cough (< 3 weeks) in Individuals with No Significant Comorbidities ( Fig. 12.1 )
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Most commonly from bronchitis (viral more so than bacterial)
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Should be self-limited
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Cough may be dry or purulent
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Purulent cough is more common in bacterial bronchitis
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Chest pain, shortness of breath, frank hemoptysis (blood without sputum), and/or high fever are not anticipated with bronchitis and should prompt a chest x-ray looking for typical or atypical pneumonia (eg, tuberculosis [TB]) and/or other pathology (eg, lung cancer, effusion, pneumothorax)
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If chest imaging is normal and a workup fails to reveal an alternate explanation, these individuals typically deserve antibiotics, given the chance that early pneumonia may explain their additional symptoms (despite a clear chest x-ray)
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Cough may be associated with significant morbidity by causing:
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Disturbed sleep
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Work absence
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Persistent blood-tinged sputum (from upper airway/large airway mucosal inflammation)
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Posttussive emesis
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Incontinence
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Rib fracture
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Syncope
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Cough suppression should be offered to those whose cough is bothersome (most individuals who seek medical attention)
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Dextromethorphan is first line because of its safety profile
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Codeine has better efficacy and should be used for dextromethorphan failures
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Antibiotics typically are not indicated for healthy individuals with acute cough but should be considered in individuals whose cough has:
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Caused persistent blood-tinged sputum
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Prevented sleep or work for more than 2 days
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Evolved from being nonproductive to purulent after several days (concerning for postviral bacterial superinfection)
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If antibiotics are used, they should cover atypical and typical community-acquired bacterial pathogens (eg, doxycycline, azithromycin)
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Individuals with recurrent posttussive emesis deserve consideration for pertussis infection and a course of macrolide antibiotics
Acute Cough (< 3 weeks) in Individuals with Lung Disease or Immunosuppression ( Fig. 12.2 )
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Individuals with lung disease or immunosuppression are at increased risk for:
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Pneumonia caused by typical bacteria, atypical bacteria, and fungal organisms
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Pneumonia with muted clinical signs (eg, dry cough, afebrile)
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Progression from bronchitis to pneumonia
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Rapid clinical deterioration, given little pulmonary and/or immunologic reserve
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Chest pain, shortness of breath, significant hemoptysis, and/or high fever are not anticipated with bronchitis and should prompt a chest x-ray looking for typical or atypical pneumonia (eg, TB) and/or other pathology (eg, lung cancer, effusion, pneumothorax)
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If chest imaging is normal and a workup fails to reveal an alternate explanation, these individuals typically deserve antibiotics, given a concern for early pneumonia
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There is a low threshold to obtain a sputum culture and prescribe empiric antibiotic therapy in individuals with lung disease or immunosuppression who have a purulent cough
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An x-ray may be unnecessary if the decision to give antibiotics has been made
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Empiric antibiotics should cover typical and atypical community-acquired bacteria (eg, respiratory quinolones or azithromycin)
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Antibiotics should also be considered in individuals whose dry cough has caused persistent blood-tinged sputum or prevented sleep or work for more than 2 days
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Cough suppression should be offered to all individuals whose cough has been disruptive
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Patients with lung disease or immunosuppression who do not appear to need empiric antibiotic therapy (eg, those with a short-duration, dry cough associated with a viral syndrome or a resolving cough) should have an x-ray obtained to ensure they do not have pneumonia (with a muted clinical presentation)
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These individuals may be managed conservatively (ie, without antibiotics) if their chest x-ray fails to show a new infiltrate
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Close clinical follow-up is warranted in all individuals with immunosuppression or lung disease who are evaluated for acute cough
