What are the possible causes of persistent cough one month after acute bronchitis?

From the Guidelines

A cough one month after bronchitis is likely postinfectious cough, and the optimal treatment is not known, but a trial of inhaled ipratropium may attenuate the cough. According to the American College of Chest Physicians (ACCP) evidence-based clinical practice guidelines 1, postinfectious cough is a common condition that occurs after an acute respiratory infection, and it is characterized by a cough that persists for at least 3 weeks, but not more than 8 weeks. The guidelines suggest that in patients with subacute postinfectious cough, it is essential to judge which factors are most likely provoking the cough before considering therapy, as there are multiple pathogenetic factors that may contribute to the cause of cough, including postviral airway inflammation, upper airway cough syndrome, asthma, and gastroesophageal reflux disease.

Some key points to consider in the management of postinfectious cough include:

• Therapy with antibiotics has no role, as the cause is not bacterial infection 1
• A trial of inhaled ipratropium may attenuate the cough, with a level of evidence rated as fair and a net benefit rated as intermediate 1
• In patients with postinfectious cough, when the cough adversely affects the patient’s quality of life and when cough persists despite use of inhaled ipratropium, consider the use of inhaled corticosteroids, with a level of evidence rated as expert opinion and a net benefit rated as intermediate 1
• Central acting antitussive agents such as codeine and dextromethorphan should be considered when other measures fail, with a level of evidence rated as expert opinion and a net benefit rated as intermediate 1

It is essential to note that if the cough persists for more than 8 weeks, worsens, produces discolored phlegm, or if the patient experiences fever, chest pain, or breathing difficulties, they should seek medical attention, as these could indicate complications or a different condition requiring medical attention.

From the Research

Cough Persistence after Bronchitis

• The cough associated with acute bronchitis typically lasts about two to three weeks 2.
• If a cough persists for more than two weeks, other conditions such as pertussis should be suspected, especially if accompanied by symptoms like paroxysmal cough, whooping cough, and post-tussive emesis 2.
• For patients with chronic obstructive pulmonary disease (COPD), including those with chronic bronchitis, exacerbations can lead to prolonged cough, and antibiotics may be indicated in severe cases or when purulent sputum is present 3, 4.

Evaluation and Management of Persistent Cough

• Chronic cough, defined as a cough lasting longer than eight weeks in adults, can be caused by various conditions, with upper airway cough syndrome, gastroesophageal reflux disease, asthma, and nonasthmatic eosinophilic bronchitis being the most common causes 5.
• Evaluation should include clinical assessment and may involve spirometry, chest radiography to rule out other conditions, and empiric treatment based on suspected causes 5.
• In the context of COPD with acute exacerbation of chronic bronchitis, treatments such as azithromycin, in addition to standard therapies like salmeterol-fluticasone and tiotropium bromide, may improve clinical outcomes and pulmonary function 6.

Considerations for Antibiotic Use

• Antibiotics are not generally recommended for acute bronchitis unless there is evidence of a bacterial infection or the patient has chronic lung disease 2.
• In cases of COPD exacerbation, antibiotics like beta-lactams and fluoroquinolones may be used, especially in severe cases or with purulent sputum 3, 4.
• The decision to use antibiotics should consider the risk of antimicrobial resistance and the potential for adverse effects 2, 4.