From the Guidelines
Bronchitis is primarily a clinical diagnosis, with the diagnostic criteria for chronic bronchitis including a productive cough occurring on most days for at least three months per year for two consecutive years, without another identifiable cause. The diagnosis of bronchitis relies heavily on the patient's history and physical examination, as laboratory tests and imaging are typically not required unless complications or alternative diagnoses are suspected 1. According to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines, chronic bronchitis is characterized by a cough and sputum expectoration occurring on most days for at least 3 months of the year and for at least 2 consecutive years, in the absence of other pulmonary or cardiac causes for the chronic productive cough 1.
Key Diagnostic Criteria
- A productive cough occurring on most days for at least three months per year for two consecutive years
- Absence of another identifiable cause for the chronic productive cough
- Additional clinical features may include fever, chest discomfort, wheezing, and rhonchi on auscultation
- Pulmonary function tests may be used in chronic cases to assess airflow limitation, as the clinical diagnosis of COPD, which includes chronic bronchitis, is suggested by symptoms but can only be established firmly by an objective measurement indicating airflow obstruction 1.
The clinical approach to diagnosing bronchitis is justified because it is predominantly an inflammatory condition of the bronchial tubes, and its diagnosis is based on recognizing this pattern of respiratory symptoms that cannot be attributed to other specific respiratory conditions like pneumonia, asthma, or heart failure. The British Thoracic Society guidelines also support this approach, emphasizing the importance of clinical diagnosis and the use of objective measurements to confirm airflow obstruction in cases of COPD, which includes chronic bronchitis 1.
From the Research
Definition and Diagnosis of Bronchitis
- Bronchitis is a clinical diagnosis characterized by cough due to acute inflammation of the trachea and large airways without evidence of pneumonia 2, 3.
- The diagnosis of bronchitis should be differentiated from other common diagnoses, such as pneumonia and asthma, because these conditions may need specific therapies not indicated for bronchitis 3.
Criteria for Diagnosis
- Cough is the most common symptom of bronchitis, and it typically lasts about two to three weeks 2, 3.
- The presence or absence of colored sputum does not reliably differentiate between bacterial and viral lower respiratory tract infections 3.
- Pneumonia should be suspected in patients with tachypnea, tachycardia, dyspnea, or lung findings suggestive of pneumonia, and radiography is warranted 2.
- Pertussis should be suspected in patients with cough persisting for more than two weeks that is accompanied by symptoms such as paroxysmal cough, whooping cough, and post-tussive emesis, or recent pertussis exposure 2.
Treatment and Management
- Acute bronchitis is usually caused by viruses, and antibiotics are not indicated in patients without chronic lung disease 2, 3, 4.
- Antibiotics have been shown to provide only minimal benefit, reducing the cough or illness by about half a day, and have adverse effects, including allergic reactions, nausea and vomiting, and Clostridium difficile infection 2.
- Evaluation and treatment of bronchitis include ruling out secondary causes for cough, such as pneumonia; educating patients about the natural course of the disease; and recommending symptomatic treatment and avoidance of unnecessary antibiotic use 2, 3.