Bronchitis is the inflammation of the bronchial respiratory mucosa with a resulting cough. In the vast majority of cases, the cause is viral; most commonly influenza, parainfluenza, rhinovirus, and respiratory syncitial virus.
Bacterial causes are more likely in cases lasting >=2 weeks, without improvement, and include:
- Mycoplasma pneumoniae
- Chlamydia pneumoniae
- Bordetella pertussis ("Whooping cough")
Data supporting no antibiotic use:
- Multiple meta-analyses evaluating acute bronchitis in adults shows no efficacy of antibiotics in decreasing duration of illness, days of sputum, limitation of activity, or loss of time from work
- Several studies in the pediatric population have had similar findings of no efficacy of antibiotics for bronchitis
- Antibiotic treatment of bronchitis does not appear efficacious in preventing or decreasing the severity of bacterial complications of viral respiratory infections
- Use of antibiotics, unnecessarily, results in increased antibiotic drug resistance, being potentially dangerous to both the patient and the broader society
Clinical considerations:
- The evaluation of patients with cough should focus on ruling out pneumonia (unlikely with no abnormalities in vital signs and no focal findings on lung exam)
- Presence of purulent sputum in no way indicates a bacterial versus viral etiology
- Consider the differential diagnosis of cough
- ACE-Inhibitor cough
- Allergies
- Asthma
- Bronchiectasis
- Bronchitis (atypical bacterial or pertussis)
- Bronchitis (chronic)
- Bronchitis (viral)
- Cystic fibrosis (Pediatric)
- Foreign body aspiration (Pediatric)
- Gastroesophageal reflux disease
- Habit cough (Pediatric)
- Malignancy
- Pneumonia
- Post-nasal drip
- Second-hand smoke/environmental exposures
- Sinusitis
- Tuberculosis
Indications that antibiotics may be needed:
- The natural history of most viral bronchitis is a cough for 1-3 weeks without signs of pneumonia
- For patients with cough persisting more than 3 weeks, a chest radiograph and review of the differential diagnosis is necessary
- In adults with COPD exacerbation, antibiotics may be indicated (benefit mostly seen in severe exacerbations)
- In children (occurs less commonly in adults) pertussis should be considered when prolonged paroxysmal coughing is present
- Associated findings with pertussis includes inspiratory whoop, post-tussive emesis, and lymphocytosis
- In children >5 years and adults, infections with Mycoplasma or Chlamydia pneumoniae may also cause prolonged cough and may benefit from antibiotic treatment
References:
- Chandran R. Should we prescribe antibiotics for acute bronchitis?. Am Fam Physician. 2001;64(1):135-8.
- Gonzales R, Steiner JF, Lum A, et al. Decreasing antibiotic use in ambulatory practice: impact of a multidimensional intervention on the treatment of uncomplicated acute bronchitis in adults. JAMA. 1999;281(16):1512-9.
- Smucny JJ, Flynn CA, Becker LA, et al. Are beta2-agonists effective treatment for acute bronchitis or acute cough in patients without underlying pulmonary disease? A systematic review. J Fam Pract. 2001;50(11):945-51.
- Smucny J, Becker L, Glazier R. Beta2-agonists for acute bronchitis. Cochrane Database Syst Rev. 2006;(4):CD001726.
- Thomas AR. Judicious use of antibiotics (Second edition). http://public.health.oregon.gov/PreventionWellness/SafeLiving/AntibioticResistance/Documents/pdfs/cme2.pdf Last accessed June 18, 2013.