Approach to Diagnosis and Management of Acute Bronchitis
Diagnosis: Rule Out More Serious Conditions First
Before diagnosing acute bronchitis, you must systematically exclude pneumonia, asthma, COPD exacerbation, and the common cold—acute bronchitis is a diagnosis of exclusion. 1
Critical Diagnostic Steps
Check vital signs and perform a focused chest examination to rule out pneumonia, which requires different management: 1, 2
- Heart rate >100 beats/min
- Respiratory rate >24 breaths/min
- Oral temperature >38°C
- Focal consolidation findings (rales, egophony, fremitus)
If any of these are present, obtain chest radiography—this is pneumonia until proven otherwise, not simple bronchitis. 1, 2
Recognize Misdiagnosed Asthma
Approximately one-third of patients diagnosed with "acute bronchitis" actually have undiagnosed asthma. 1, 2 If the patient has had at least two similar episodes in the past 5 years, 65% will have mild asthma rather than recurrent infections. 1 The only way to distinguish these is prospective follow-up to determine if this is an isolated event or a pattern suggesting chronic disease. 1
Exclude COPD Exacerbation
Patients with known COPD presenting with acute cough should be evaluated for exacerbation rather than simple acute bronchitis. 1 These patients require different management and are not candidates for the standard acute bronchitis approach. 1
Management: Antibiotics Are NOT Indicated
Antibiotics should NOT be prescribed for acute bronchitis in otherwise healthy adults—they reduce cough duration by only 0.5 days while exposing patients to significant adverse effects and contributing to antibiotic resistance. 2, 3, 4
Why Antibiotics Don't Work
Respiratory viruses cause 89-95% of acute bronchitis cases. 2, 3, 4, 5 Bacterial infections account for fewer than 10% of cases. 1, 5 Purulent or green sputum does NOT indicate bacterial infection—it occurs in 89-95% of viral cases and is not an indication for antibiotics. 1, 2
The Single Exception: Pertussis
If pertussis (whooping cough) is confirmed or strongly suspected, prescribe a macrolide antibiotic (erythromycin or azithromycin) immediately and isolate the patient for 5 days from the start of treatment. 1, 2 Early treatment within the first few weeks diminishes coughing paroxysms and prevents disease spread. 1, 2
Symptomatic Treatment Options
What May Help (Modestly)
Codeine or dextromethorphan can provide modest relief for bothersome dry cough, especially when sleep is disturbed. 2, 4 The effects are limited but these agents are low-risk options. 2
β2-agonist bronchodilators should NOT be routinely used but may be considered in select adult patients with accompanying wheezing. 2, 4 Most patients with acute bronchitis do not benefit from bronchodilators. 2
What Does NOT Work
- Oral corticosteroids (including prednisone)
- Inhaled corticosteroids
- NSAIDs at anti-inflammatory doses
- Expectorants or mucolytics
- Antihistamines
- Anticholinergics
These have not been shown to improve outcomes in acute bronchitis. 2, 6, 4
Patient Education: The Key to Satisfaction
Inform patients that cough typically lasts 10-14 days after the visit, even without treatment, and may persist up to 3 weeks. 2, 7, 4 Setting realistic expectations is crucial—most patients seek care within the first week, expecting rapid resolution. 1
Refer to the condition as a "chest cold" rather than "bronchitis" to reduce patient expectations for antibiotics. 2, 4 Studies show that 44% of patients expect antibiotics for "bronchitis" compared to only 11% for "chest colds." 1
Patient satisfaction depends more on the quality of physician-patient communication than whether an antibiotic is prescribed. 2, 8 Explain why antibiotics are harmful in this situation: they expose patients to adverse effects while contributing to antibiotic resistance without providing meaningful benefit. 2, 4
When to Reassess
Instruct patients to return if: 2, 7
- Fever persists beyond 3 days (suggests bacterial superinfection or pneumonia)
- Cough persists beyond 3 weeks (consider asthma, COPD, pertussis, gastroesophageal reflux disease, or upper airway cough syndrome)
- Symptoms worsen rather than gradually improve
Fever persisting beyond 3 days strongly suggests bacterial superinfection or pneumonia rather than uncomplicated viral bronchitis. 2, 7 Cough persisting beyond 3 weeks transitions to subacute cough and requires evaluation for alternative diagnoses. 1, 7
Special Populations: High-Risk Patients
These recommendations apply ONLY to otherwise healthy adults with uncomplicated acute bronchitis. 1 Patients with underlying conditions require different management:
COPD Exacerbation (Not Simple Acute Bronchitis)
For patients with known COPD presenting with acute worsening, consider antibiotics if they have at least 2 of the 3 Anthonisen criteria: 2
- Increased dyspnea
- Increased sputum volume
- Increased sputum purulence
First-line antibiotics for COPD exacerbation: doxycycline 100 mg twice daily for 7-10 days or amoxicillin 500 mg three times daily for 7-10 days. 2
For severe exacerbations or high-risk patients (age >65, FEV1 <35%, cardiac failure, diabetes): amoxicillin/clavulanate 625 mg three times daily for 14 days. 2
Other High-Risk Groups
Patients with congestive heart failure, immunosuppression (AIDS, chemotherapy), or bronchiectasis are at high risk for complications and require individualized management outside the scope of standard acute bronchitis treatment. 1
Common Pitfalls to Avoid
Do not diagnose acute bronchitis over the phone—you must examine the patient to exclude pneumonia and other serious conditions. 9
Do not assume bacterial infection based on: 1, 2
- Sputum color or purulence (occurs in 89-95% of viral cases)
- Duration of cough (viral bronchitis cough lasts 10-14 days normally)
- Patient expectation for antibiotics
Do not confuse acute bronchitis with asthma or COPD exacerbation—these require different treatments including bronchodilators and potentially corticosteroids. 1, 6 Approximately 40% of patients develop transient bronchial hyperresponsiveness during acute viral respiratory infection, which resolves within 6 weeks. 7
Do not prescribe antibiotics "just in case" or as delayed prescriptions for simple acute bronchitis—this perpetuates inappropriate antibiotic use and patient expectations. 2, 4