Chronic Cough: Evaluation and Management

Charlie Michaudet, MD; John Malaty, MD

Disclosures

Am Fam Physician. 2017;96(9):575-580. 

In This Article

Common Causes of Chronic Cough

Upper Airway Cough Syndrome

The term UACS, previously referred to as postnasal drip syndrome, was coined in the 2006 American College of Chest Physicians guideline[4] in recognition of the fact that multiple etiologies, including chronic rhinosinusitis, allergic rhinitis, and nonallergic rhinitis, were difficult to differentiate solely by clinical presentation. UACS is the most common cause of chronic cough.[10] Rhinorrhea, nasal stuffiness, sneezing, itching, and postnasal drainage suggest the diagnosis, but their absence does not rule out UACS.[11] Physical findings may include swollen turbinates and direct visualization of postnasal drainage and cobblestoning of the posterior pharynx. If a specific cause is identified, therapy should be started; otherwise, initial treatment includes a decongestant combined with a first-generation antihistamine. Intranasal corticosteroids, saline nasal rinses, nasal anticholinergics, and antihistamines are also reasonable options.[10] Clinical improvement should occur within days to weeks, and up to two months. If chronic rhinosinusitis is suspected, sinus computed tomography or flexible nasolaryngoscopy should be performed. Sinus radiography is not recommended because of limited sensitivity.[12]

Asthma and Copd

The prevalence of asthma in patients with chronic cough ranges from 24% to 29%.[13] It should be suspected in patients with shortness of breath, wheezing, and chest tightness, but cough can be the only manifestation in cough variant asthma. If the physical examination and spirometry findings are nondiagnostic, bronchial challenge testing (methacholine inhalation test) should be considered.[14] Resolution of the cough after asthma treatment is also diagnostic. After counseling the patient about potential triggers, treatment usually includes an inhaled bronchodilator and high-dose inhaled corticosteroid. A leukotriene receptor antagonist (e.g., montelukast [Singulair]) can also be useful. Symptoms should resolve within one to two weeks after starting treatment.[15–17] For severe or refractory cough, a five- to 10-day course of prednisone, 40 to 60 mg, or equivalent oral corticosteroid can be considered if asthma is strongly suspected.[4,13]

COPD commonly causes chronic cough, but most patients presenting with chronic cough do not have undiagnosed COPD. Signs and symptoms suggestive of asthma also occur in persons with COPD. Spirometry is diagnostic, and purulent sputum production may also be present. Treatment includes an inhaled bronchodilator, inhaled anticholinergic, inhaled corticosteroid, and a one- to two-week course of oral corticosteroids (with or without antibiotics).[18]

Nonasthmatic Eosinophilic Bronchitis

Nonasthmatic eosinophilic bronchitis is characterized by chronic cough in patients with no symptoms or objective evidence of variable airflow obstruction, normal airway responsiveness on a methacholine inhalation test, and sputum eosinophilia.[19] Sputum evaluation is not typically performed in the primary care setting, but it can be induced by saline nebulization or obtained by bron-choalveolar lavage in a subspecialist's office. The prevalence is unclear, but studies assessing airway inflammation in patients with chronic cough showed that this condition accounts for 10% to 30% of cases referred for subspecialist investigation.[14,20] It does not respond to inhaled bronchodilators, but should respond to inhaled corticosteroids. Avoidance strategies should be recommended when the inflammation is due to occupational exposure or inhaled allergens. Oral corticosteroids are rarely needed but can be considered if high-dose inhaled corticosteroids are ineffective.[14]

Gastroesophageal/Laryngopharyngeal Reflux Disease

The prevalence of GERD and laryngopharyngeal reflux disease as causative factors in chronic cough varies from 0% to 73%.[21] Studies have shown an association between GERD and chronic cough, but the pathophysiology is complex and treatment is controversial.[2,22,23] Associated manifestations such as heartburn, regurgitation, sour taste, hoarseness, and globus sensation are clinical clues. Although several uncontrolled studies have shown improvement of chronic cough with antacid treatment, more recent randomized controlled trials have shown no differences between proton pump inhibitors and placebo.[24–29] Although there is poor evidence that proton pump inhibitors are universally beneficial for GERD-induced chronic cough,[30] consensus guidelines recommend empiric therapy for at least eight weeks in conjunction with lifestyle changes such as dietary changes and weight loss.[4,31] The addition of a histamine H2 receptor antagonist and/or baclofen (Lioresal, 20 mg per day) may be helpful.[32,33]

A link between obstructive sleep apnea and chronic cough has been investigated. Treatment with continuous positive airway pressure may improve chronic cough by decreasing GERD; therefore, evaluation for obstructive sleep apnea should be considered.[34] Surgery can be considered in patients with GERD-associated chronic cough who have abnormal esophageal acid exposure (as proven by pH testing) if normal peristalsis is confirmed on manometry.[31]

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