Acute Bronchitis

See Also

Definition

Infection of trachea, Bronchi, or Bronchioles
Acute Bronchitis is most often of viral etiology
1. Contrast with Chronic Bronchitis exacerbation (COPD exacerbation) which is often Bacterial

Epidemiology

Acute Bronchitis is most common cause of acute cough
1. Cough is most common presenting symptom in primary care

Etiology
Most common causes by age

Age under one year
1. Respiratory Syncytial Virus (winter to spring)
2. Parainfluenza Virus (fall)
3. Coronavirus (winter to spring)
Age one to 10 years
1. Parainfluenza Virus (fall)
2. Enterovirus (fall)
3. Respiratory Syncytial Virus (winter to spring)
4. Rhinovirus (fall)
Age over 10 years
1. Influenza Virus (winter to spring)
2. Respiratory Syncytial Virus (winter to spring)
3. Adenovirus

Etiology
By Category

Viral Causes (represent >90% of causes)
1. Adenovirus
2. Coronavirus
3. Influenza
4. Metapneumovirus
5. Parainfluenza virus
6. Respiratory Syncytial Virus (RSV)
7. Rhinovirus
Bacterial causes (1-10% of causes)
1. Streptococcus Pneumoniae (Pneumococcus)
2. Haemophilus Influenzae
3. Moraxella catarrhalis (Branhamella catarrhalis)
4. Atypical Bacterial causes
  1. Bordetella pertussis (and parapertussis)
    1. Accounts for 10% of cough lasting >2 weeks
    2. More prevalent in children during outbreaks
  2. Mycoplasma pneumoniae
  3. Chlamydia pneumoniae
  4. Legionella
Yeast or fungi
1. Blastomyces dermatitidis
2. Candida albicans (and tropicalis)
3. Coccidioides immitis
4. Cryptococcus neoformans
5. Histoplasma capsulatum
Environmental irritants (noninfectious triggers)
1. Air Pollution
2. Ammonia
3. Marijuana
4. Tobacco smoke

Symptoms

Respiratory symptoms
1. Cough (onset within 2 days in 85% of Acute Bronchitis)
  1. Cough often dry, non-productive
  2. Productive cough of variable color Sputum is common (and does not distinguish from Pneumonia)
2. Dyspnea
3. Wheezing
4. Chest Pain
5. Hoarseness
6. Nasal congestion
Constitutional and other symptoms
1. Low-Grade Fever (one third of patients)
  1. In fever (>100-101 F), consider Influenza or Pneumonia
2. Myalgias
3. Fatigue
4. Headache

Signs

Low grade fever
1. High fever suggests Pneumonia or Influenza
Lung auscultation
1. Rhonchi variably present (clear with coughing)
2. Wheezing
3. Prolonged expiration
4. No signs of consolidation (Pneumonia)
  1. Lung sounds symmetric
  2. No focal rales

Diagnostics
Optional

Approach
1. Testing is not typically performed in Acute Bronchitis
2. Consider diagnostics when red flag findings are present
Sputum exam
1. Not indicated unless Pneumonia suspected
Pulse Oximetry
1. Consider in Dyspnea, Tachypnea or ill appearance
Peak Flow values
1. Consider in Asthma history
C-Reactive Protein (CRP)
1. CRP <50 mcg/ml suggests Acute Bronchitis (instead of Pneumonia), especially if no daily fever or Dyspnea
2. Held (2012) BMC Infect Dis 12:355 [PubMed]
3. Hopstaken (2003) Br J Gen Pract 53:358-64 [PubMed]
Other specific organism testing
1. Pertussis PCR
2. Rapid Influenza Test

Imaging
Chest XRay Indications

Chest XRay is not required in young, otherwise healthy patients without red flag findings
1. Pneumonia is unlikely with normal Vital Signs and normal Lung Exam
Red flag history findings
1. Significant Dyspnea
2. Bloody Sputum or rust colored Sputum
Red flag exam findings
1. Fever >100-101 F
2. Tachypnea (adult Respiratory Rate >24/min)
3. Hypoxia
4. Tachycardia
5. Asymmetric lung sounds (e.g. focal decreased breath sounds)
6. Ill appearance
Pulmonary cause of cough suspected
1. Pneumonia
2. Congestive Heart Failure
Older patient or serious comorbid condition
1. Elderly patient (Pneumonia may present without fever, Tachycardia or Tachypnea)
2. Chronic Obstructive Lung Disease
3. Immunocompromised patient
4. Malignancy history
5. Recent history of pulmonary process
  1. Pneumonia
  2. Tuberculosis

Differential Diagnosis

See Acute Cough Causes
Obstructive Lung Disease
1. Asthma
2. Acute Exacerbation of Chronic Bronchitis (COPD)
Other infection
1. Rhinitis or Sinusitis with post-nasal drainage
2. Influenza
3. Pneumonia
  1. Predictors
    1. C-Reactive Protein >20
    2. Erythrocyte sedimentaion rate increased
    3. Dry cough with Diarrhea, Nausea
    4. Temperature >38 C (>100.4 F)
  2. References
    1. Hopstaken (2003) Br J Gen Pract 53:358-64 [PubMed]
Other conditions
1. Congestive Heart Failure

Management
Symptomatic

Precautions
1. Cough Suppression risks worsening bronchospasm (esp. Asthma and COPD)
2. Avoid Albuterol Syrup (Not helpful and potentially harmful)
  1. Littenberg 1996 J Fam Pract 42:49-53) [PubMed]
3. Although found beneficial in some trials, high dose Inhaled Corticosteroids are not used in standard Acute Bronchitis
  1. McKean (2000) Cochrane Database Syst Rev CD001107 [PubMed]
4. Avoid Systemic Corticosteroids in Acute Bronchitis (aside from acute COPD or Asthma Exacerbation)
  1. Hay (2017) JAMA 318(8): 721-30 [PubMed]
Supportive care for viral illness
Inhaled Bronchodilator (e.g. Albuterol)
1. More recent reviews suggest no benefit in Bronchitis unless Wheezing (or Asthma or COPD history)
  1. Direct use to those with Wheezing on examination
  2. Schroeder (2004) Cochrane Database Syst Rev CD001831
2. Initial review suggested benefit in shortening Bronchitis course
  1. Hueston (1994) J Fam Pract 39:437-40 [PubMed]
Symptomatic relief of cough (especially nighttime)
1. See Cough Suppressant (Antitussive)
2. Adults
  1. Guaifenesin (Cough Expectorant)
    1. Smith (2014) Cochrane Database Syst Rev (11):CD001831 [PubMed]
  2. Dextromethorphan (Cough Suppressant)
    1. Smith (2014) Cochrane Database Syst Rev (11):CD001831 [PubMed]
  3. Benzonatate (Tessalon, Cough Suppressant)
    1. Effective when used with Guaifenesin in small study
    2. Dicpingaitis (2009) Respir Med 103(6): 902-6 [PubMed]
3. Children
  1. Honey appears effective in reducing cough in children
    1. Do not use in age <1 year (Botulism risk)
    2. Oduwole (2014) Cochrane Database Syst Rev (12):CD007094 +PMID:22419319 [PubMed]
  2. Dextromethorphan is not effective in children with Bronchitis
    1. Paul (2004) Pediatrics 114(1):e85-90 [PubMed]
Pelargonium sidoides (herbal product)
1. Decreases overall symptoms and return to work time compared with Placebo
2. However, low quality evidence
3. Matthys (2003) Phytomedicine 10:7-17 [PubMed]

Management
Specific Circumstances

Treat suspected underlying cause of cough
1. See Cough Management
2. See Chronic Cough
Persistent post-Bronchitic cough
1. Bronchodilators reduce symptom severity and duration
2. Consider Inhaled Corticosteroid (e.g. Azmacort)

Management
Antibiotics

Most cases are viral and do not require Antibiotics
1. Most studies show minimal if any Antibiotic benefit
  1. No benefit with Azithromycin
  2. Evans (2002) Lancet 359:1648-54 [PubMed]
2. Patients with cough under 1 week showed no benefit
3. Most patients improve with or without Antibiotics
4. See Antibiotic Resistance for Patient Education
Productive cough short duration (<1 week)
1. Avoid Antibiotics
2. Treat symptomatically as above
Productive cough longer than 1-2 weeks
1. Evaluate for treatable and serious causes of cough
  1. Pneumonia (consider Chest XRay)
  2. Acute Sinusitis
  3. Bordatella Pertussis
  4. Influenza A (treat within first 36 hours of symptoms)
  5. Tuberculosis (consider PPD or Quantiferon-TB)
2. Reassurance
  1. Observation is reasonable if otherwise healthy
  2. Bronchitis often lasts >2 weeks (see course below)
  3. Consider Inhaled Corticosteroid (not typically used)
  4. Even Pertussis course is not significantly modified with Antibiotics (esp. at >2 weeks of symptoms)
    1. However, Antibiotics do decrease transmission risk (Infectivity)
3. Antibiotic protocol
  1. Consider delayed Antibiotic strategy
    1. Prescription given that may be filled at a later date if not improving
    2. Results in similar outcomes to other strategies, with less Antibiotic use, and fewer return visits
    3. Little (2017) BMJ 357:j2148 +PMID:28533265 [PubMed]
    4. Little (2014) BMJ 248:g1606 [PubMed]
  2. Consider using acute phase reactant markers to distinguish higher risk cases
    1. Procalcitonin
      1. Christ-Crain (2004) Lancet 363(9409):600-7 [PubMed]
    2. C-Reactive Protein
      1. Cals (2009) BMJ 338: b1374 [PubMed]
  3. Consider treating high risk groups
    1. Age over 65 years
    2. Chronic Obstructive Lung Disease
      1. See Acute Exacerbation of Chronic Bronchitis
  4. Antibiotics have no benefit empirically in Bronchitis
    1. Evans (2002) Lancet 359(9318): 1648-54 [PubMed]
    2. Smucny (1998) J Fam Pract 47(6): 453-60 [PubMed]
  5. Antibiotic selection (empiric use not recommended)
    1. Adult under age 50 years
      1. Macrolide Antibiotic or
      2. Doxycycline
    2. Adult over age 50 years
      1. Third Generation Fluoroquinolone (e.g. Levaquin)

Precautions

Avoid suppressing cough if possible (esp. during daytime hours)
1. Cough intended to clear lungs, protect from Pneumonia

Course

Cough persists for >2 weeks in 25% of patients (median duration 18 days)
Cough may persist as long as 8 weeks in some patients

Resources
Patient Education

Information from your Family Doctor
1. http://www.familydoctor.org/handouts/677.html

References