Acute bronchitis

Question 1

What is acute bronchitis?

Answer 1

Lower respiratory tract infection (LRTI) characterised by inflammation of the bronchi
- Result of inflammation of the trachea and major bronchi and is therefore associated with oedematous large airways and the production of sputum

Question 2

What causes bronchitis?

Answer 2

• Often follows an URTI (Upper Respiratory Tract Infection)
• Majority of cases are Viral (Influenza A, Influenza B, Parainfluenza, RSV, Coronavirus, Adenovirus)

Question 3

What are the risk factors for bronchitis?

Answer 3

Smoking, COPD, cystic fibrosis or conditions leading to bronchiectasis (anything that affects bronchial clearance) 

Question 4

What are the presenting symptoms/ signs of bronchitis?

Answer 4

1. Cough → lasts <30 days, productive (clear sputum)
2. Fever
3. Preceding URTI → runny nose, sore throat, headache
4. No hx of chronic respiratory illness

Differentiating from pneumonia:
- History: Sputum, wheeze, breathlessness may be absent in acute bronchitis whereas at least one tends to be present in pneumonia.
- Examination: No other focal chest signs (dullness to percussion, crepitations, bronchial breathing) in acute bronchitis other than wheeze. Moreover, systemic features (malaise, myalgia, and fever) may be absent in acute bronchitis, whereas they tend to be present in pneumonia.

Question 5

What investigations are used to diagnose/ manage acute bronchitis?

Answer 5

1. Generally diagnosed clinically, tests to exclude other diagnoses.
2. Pulmonary Function Test → will improve over time with acute bronchitis (as oppose to asthma)
3. CXR → rule out pneumonia as cause of cough and fever
4. CRP → may guide whether antibiotics are needed or not 

Question 6

How is bronchitis managed?

Answer 6

1. Analgesia & Good Fluid Intake
2. If pre-existing comorbidities or raised CRP → consider antibiotics
   - 1st Line ⇒ Oral Doxycycline
   - Alternative (eg. amoxicillin) should be used if pregnant woman or a child
3. If cough >4 weeks, evaluate for other causes