Differential Diagnoses for Coarse Rhonchi
When you hear coarse rhonchi on examination, prioritize bronchiectasis, COPD, acute/chronic bronchitis, and pneumonia as your primary differential diagnoses, recognizing that rhonchi indicate airway secretions or obstruction but cannot reliably predict the specific underlying condition or severity. 1, 2
Understanding Rhonchi Characteristics
Rhonchi are low-pitched continuous adventitious lung sounds with a dominant frequency of approximately 200 Hz or less, most prominent during forced expiration. 1, 3 A key distinguishing feature is that rhonchi may clear or change after coughing as secretions move, unlike other adventitious sounds. 1, 2
Primary Differential Diagnoses
Bronchiectasis
- Physical examination commonly reveals variable degrees of rhonchi, crackles, and clubbing, though findings may be entirely normal in some cases. 2
- Look for chronic productive cough with large volumes of purulent sputum. 2
- High-resolution CT (HRCT) is the diagnostic procedure of choice when bronchiectasis is suspected, as the presence or absence of crackles and rhonchi does not reliably correlate with HRCT findings. 2
Chronic Obstructive Pulmonary Disease (COPD)
- Rhonchi reflect underlying chronic obstructive lung disease pathology, though physical findings are nonspecific and often coexist with other pulmonary conditions. 2
- Patients typically present with cough, sputum production, and breathlessness. 4
- Smokers with persistent cough may be at risk of developing COPD. 4
Acute and Chronic Bronchitis
- Rhonchi are commonly found in conditions causing airway secretions or obstruction, including both acute and chronic bronchitis. 1, 2
- Consider pertussis infection in patients with persistent cough, as studies show 10% of chronic cough cases had positive nasal swabs for Bordetella. 4
Pneumonia
- Rhonchi may be present in pneumonia, though in pediatric populations, rhonchi alone (without tachypnea, rales, or decreased breath sounds) do not significantly increase the likelihood of pneumonia on chest radiograph. 2
- Look for associated fever, productive cough, and systemic symptoms. 5
Less Common but Important Differentials
Aspiration/Foreign Body
- Consider in patients with sudden onset symptoms or history suggesting aspiration risk. 4
- Particularly important in neonates and young children. 4
Tracheobronchitis
- Can present with rhonchi, hemoptysis, and dyspnea. 6
- MRSA tracheobronchitis is rare but fulminant when it occurs. 6
Unusual Presentations
- Left atrial myxoma can rarely present as refractory wheeze with rhonchi, particularly when symptoms are unresponsive to standard bronchodilator therapy. 7
- Consider cardiac causes when respiratory symptoms are refractory to appropriate treatment. 7
Diagnostic Approach
Initial Workup
- Obtain a chest radiograph in all patients with chronic cough and rhonchi; 31% of chest radiographs requested for persistent cough yield abnormal findings or a diagnosis. 4
- Assess for associated findings: sputum production volume and character, clubbing, fever, weight loss, hemoptysis. 4, 2
Advanced Testing When Indicated
- Consider HRCT if bronchiectasis is suspected, as it is the diagnostic procedure of choice. 2
- Perform pulmonary function testing to assess degree of obstruction. 2
- Obtain sputum cultures if chronic productive cough is present. 2
Red Flags Requiring Urgent Evaluation
- Hemoptysis, dysphagia, odynophagia, or otalgia. 4
- History of tobacco or alcohol use. 4
- Concomitant neck mass. 4
- Unexplained weight loss. 4
- Symptoms refractory to appropriate treatment (consider unusual causes like cardiac pathology). 7
Key Clinical Pitfalls
Rhonchi are not sufficiently diagnostic to determine the specific underlying condition and must be interpreted with other clinical findings. 1, 2 The presence of rhonchi does not reliably predict the severity of airway obstruction. 1, 2
Do not delay chest imaging based solely on physical examination findings, as the correlation between auscultatory findings and radiographic abnormalities is poor. 2