1. Etiology
1.1. Can be caused by infection or irritation exposure like smoke (5)
1.2. 90% of cases caused by viruses (1)
1.2.1. Most common viral causes are influenza, parainfluenza, respiratory syncytial virus, and rhinovirus (2)
1.3. Bacteria are uncommon causes, accounting for <10% of cases (2)
2. Pathophysiology
2.1. Lower respiratory tract infection characterized by self-limiting inflammation of the large airways and bronchi (1, 5)
2.2. Inflammation causes mucus production and persistent coughing (2)
3. Risk Factors
3.1. Exposure to infected individuals
3.2. Smoking or smoke exposure
3.3. Immunocompromised
3.4. Recent respiratory infection
4. Causative Factors
4.1. Viruses (90% cases)
4.2. Bacteria (<10% cases)
5. Diagnostic Tests
5.1. Pulmonary function test
5.1.1. Can have reduced forced expiratory volume (2)
5.1.2. Not usually indicated in clinical practice (2)
5.2. Chest X-ray
5.2.1. Normal or nonspecific findings such as thickening of bronchial walls in lower lobes (2)
5.2.2. Only indicated with abnormal vital signs, altered mental status in the elderly over 75 years old, or signs of consolidation on physical examination of the chest (2)
5.3. Sputum Culture
5.3.1. Rarely indicated as it is usually viral etiology so findings would not alter treatment plan (2)
5.3.2. Indicated for patients at high risk for complications or immunocompromised (2)
5.4. COVID-19 Test
5.4.1. Coronaviruses have been causes of acute bronchitis and a COVID-19 infection can precede the development of acute bronchitis (2)
6. Symptoms
6.1. Persistent cough with or without purulent sputum, chills, fever, malaise (1)
6.1.1. Lasts 1-3 weeks (2)
6.2. Wheezing and mild dyspnea depending on severity of infection (2)
6.3. Chest wall pain from prolonged coughing (2)
7. Exam Findings
7.1. Nonproductive cough (5)
7.2. Diminished to clear lung sounds, may have wheezing if large lung field involvement (5)
7.3. Possible low grade fever (5)
7.4. Chest pain or tenderness from coughing (5)
8. Treatments
8.1. Antitussives for cough (1)
8.1.1. OTC dextromethorphan or guaifenesin (6)
8.2. Supportive care for cough
8.2.1. Throat lozenges (2)
8.2.2. Hot tea with honey (2)
8.2.3. Smoking cessation (2)
8.3. Beta agonist for wheezing (1)
8.3.1. Albuterol inhaler 2 puffs every 4-6 hours (can help reduce bronchospasm) (6)
8.3.2. Reserved for patients with wheezing (2)
8.4. Avoid antibiotic use
8.4.1. Most cases caused by viruses so antibiotics would not shorten the course of illness (1)
8.4.2. Can contribute to antibiotic resistance (3)
8.4.3. Increases the risk of adverse reactions to medications (4)