Empyema differential diagnosis
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Empyema Microchapters |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Differential diagnosis
Empyema must be diffrentiated from pneumonia, lung abscess, lung cancer and parapneumonic effusions as shown below:
| Variable | Empyema Thoracis | Lung abscess | Pleural effusion | Pneumonia | Lung cancer |
|---|---|---|---|---|---|
| Presentation | Variable presentation but may follow long standing pneumonia | Usually has history of aspiration pneumonia, alcoholics, drug abusers, seizure disorder, have undergone recent general anesthesia, or have a nasogastric or endotracheal tube. | Usually follows pneumonia as a complication | presents with fever, pleuritc chest pain, cough | mostly asymptomatic but may have cough productive with hemoptysis and chronic history of smoking |
| Causes | In general any bacteria can cause an empyema, however different bacteria are associated with different rates of empyema formation.[1] Common causes include bacteroides, fusobacterium, haemophilus influenzae, pneumococcal infections, staphylococcus aureus, streptococcus, TB | Lung abscess is commonly caused by bacterial infections and these include bacteroides, peptostreptococcus and prevotella mostly after aspiration | Common causes of transudative pleural effusion include;[1][2][3][4][5] left ventricular failure, Nephrotic syndrome, and cirrhosis, while common causes of exudative pleural effusions[6] are bacterial pneumonia and malignancy | Pneumonia can result from a variety of causes, including infection with bacteria, viruses, fungi, parasites, and chemical injury to the lungs | Direct cause of lung cancers is DNA mutations that often result in either activation of proto-oncogenes (e.g. K-RAS) or the inactivation of tumors suppressor genes (e.g. TP53) or both. The risk of these genetic mutations may be increased following exposure to environmental components example smoking |
| Laboratory findings | Laboratory findings are non specific example leukocytosis, sputum samples for gram staining and culture. Other tests include urine antigen test, PCR, C-reactive protein and procalcitonin | ||||
| Physical examination | |||||
| CXR | A homogenous opacification is noted at the affected side. The costophrenic angle is obliterated with a meniscus. | ||||
| Chest ultrasound | Ultrasound in empyema is positive for suspended microbubble sign, air fluid level, curtains sign and loss of gliding sign.[1] | Ultrasound in lung abscess is negative for suspended microbubble sign, curtains sign and loss of gliding sign but air fluid level may be seen,.[2] | |||
| CT scan | Seen as a lung mass whose cavity is regular with smooth and regular lumen, well-defined defined boundary and shape changes with change in patient's position.[3] Mass may resolve on antibiotics
The split pleura sign is present (most reliable sign to differentiate empyema from lung abscess) |
Lung mass whose cavity is rregular with undulated lumen, irregular-poorly defined boundary and shape does not change with change in patient's position.[4] Mass may resolve on antibiotics | Seen as a lung spiculated irregular solid mass that does not resolve on antibiotics |
References
- ↑ Lin FC, Chou CW, Chang SC (2004). "Differentiating pyopneumothorax and peripheral lung abscess: chest ultrasonography". Am J Med Sci. 327 (6): 330–5. PMID 15201646.
- ↑ Lin FC, Chou CW, Chang SC (2004). "Differentiating pyopneumothorax and peripheral lung abscess: chest ultrasonography". Am J Med Sci. 327 (6): 330–5. PMID 15201646.
- ↑ Baber CE, Hedlund LW, Oddson TA, Putman CE (1980). "Differentiating empyemas and peripheral pulmonary abscesses: the value of computed tomography". Radiology. 135 (3): 755–8. doi:10.1148/radiology.135.3.7384467. PMID 7384467.
- ↑ Baber CE, Hedlund LW, Oddson TA, Putman CE (1980). "Differentiating empyemas and peripheral pulmonary abscesses: the value of computed tomography". Radiology. 135 (3): 755–8. doi:10.1148/radiology.135.3.7384467. PMID 7384467.