What are the symptoms of acute bronchitis?

Symptoms of Acute Bronchitis

Acute bronchitis is characterized primarily by cough with or without phlegm production lasting up to 3 weeks, and is usually a self-limited respiratory disorder that does not require antibiotic treatment in most cases. 1

Primary Symptoms

• Cough: The hallmark symptom, typically lasting 2-3 weeks 1, 2

  • May initially be dry before developing into a productive cough 3
  • Cough prevalence is as high as 83% within the first 2 days of illness 1

• Sputum production: Often present but not required for diagnosis 1, 4

  • Purulent (colored) sputum does not reliably indicate bacterial infection 5
  • The presence of purulent sputum should not be used to distinguish between pneumonia and acute bronchitis 1

• Constitutional symptoms: May accompany the cough 1, 3

  • Fever (though typically low-grade) 1
  • Muscle aches and fatigue 1
  • Sore throat 1

Associated Respiratory Findings

• Transient airflow obstruction: Occurs in approximately 40% of previously healthy individuals with acute respiratory infections 1, 3

  • Typically resolves within 6 weeks 1
  • Reversibility of FEV1 >15% has been demonstrated in 17% of patients 1

• Transient bronchial hyperresponsiveness: Common during the illness 1, 3

  • May persist for up to 6 weeks 1

Differentiating from Other Conditions

• Pneumonia: Should be ruled out in patients with acute cough 1

  • Absence of the following findings reduces likelihood of pneumonia:
    • Heart rate >100 beats/min 1
    • Respiratory rate >24 breaths/min 1
    • Oral temperature >38°C 1
    • Chest examination findings of focal consolidation, egophony, or fremitus 1

• Common cold: Often difficult to distinguish from acute bronchitis 1

  • Cold symptoms typically include more prominent nasal stuffiness, discharge, and sneezing 1
  • Upper airway cough syndrome with throat clearing and sensation of postnasal drip is more common in colds 1, 3

• Asthma: Commonly misdiagnosed as acute bronchitis 1

  • Approximately one-third of patients presenting with acute cough diagnosed with bronchitis may actually have asthma 1, 3
  • For patients with ≥2 similar episodes of "acute bronchitis" in the past 5 years, 65% can be identified as having mild asthma 1

• Pertussis: Should be suspected with specific symptoms 2

  • Cough persisting >2 weeks 2
  • Paroxysmal cough, whooping cough, post-tussive emesis 2
  • Recent pertussis exposure 2

Duration and Course

• Symptoms typically last about 3 weeks 1, 5, 2
• The cough may persist longer in some patients 1
• When cough persists >3 weeks, other diagnoses should be considered:
  • Postinfectious cough 1
  • Upper airway cough syndrome 1
  • Asthma 1
  • Gastroesophageal reflux disease 1

Clinical Pitfalls to Avoid

• Misdiagnosis of asthma: Prospective evaluation may be needed to determine if "acute bronchitis" is an isolated event or an early presentation of asthma 1, 3

• Inappropriate antibiotic use: Viruses cause >90% of acute bronchitis cases, making antibiotics generally unnecessary 5, 2, 4

• Failure to rule out pneumonia: Especially important in elderly patients who may present with fewer typical symptoms 1

• Overlooking pertussis: Consider in patients with prolonged or paroxysmal cough 2

Understanding these symptoms helps distinguish acute bronchitis from other respiratory conditions and guides appropriate management, which primarily focuses on symptom relief rather than antibiotics in most cases.