Lung Abscess– Causes, Symptoms, Diagnosis, Treatment and Ongoing care



A localized collection cavity of necrotic lung tissue and pus resulting from pyogenic bacteria (1):

  • Presentation may be acute or chronic (symptoms for >4 weeks).
  • Usual course is subacute progression of symptoms.
  • Synonym(s): Pulmonary abscess



  • Predominant age: Mainly 4th–6th decades
  • Predominant sex: Male > Female (4:1)


Unknown; relatively rare since advent of antibiotics (2)

Pediatric Considerations

Staphylococcus most common organism in children

Risk Factors

  • Periodontal disease (gingivitis), dental abscess, dental surgery
  • Risk for aspiration:
    • Alcohol intoxication (loss of consciousness) is most common cause of aspiration (1).
    • Epilepsy
    • Cerebrovascular accident (CVA) with oropharyngeal dysfunction
    • Sinusitis
    • General anesthesia with surgery
    • Dysphagia
    • Tracheal/nasogastric tube
    • Severe gastroesophageal reflux disease (GERD)
    • Cerebral palsy
  • Large bacterial burden:
    • Necrotizing pneumonia
    • Bacteremia (especially Staphylococcus)
    • Septic embolism (especially in endocarditis)
    • Disseminated septic phlebitis
  • Airway obstruction:
    • Bronchial stenosis
    • Pulmonary embolism
    • Cavitary infarction
    • Lung neoplasia
    • Enlarged lymph node
    • Foreign body: Stent-associated respiratory tract infection (SARTI) (3)
  • Immunocompromise:
    • Diabetes mellitus
    • HIV infection
    • Chronic steroid use
  • Amebic lung abscess: Most often from direct extension from liver abscess through the diaphragm to the right lower lobe


  • No known genetic pattern
  • Immunodeficiency associated with FCN3 mutation, and ficolin-3 deficiency may predispose patients to lung infections (4).

General Prevention

  • Treatment of predisposing diseases
  • Aspiration precautions
  • Treatment of periodontal diseases


  • May be due to aspiration of anaerobic oral flora (most common); 24–48 h after aspiration, lung abscess forms (1).
  • Less commonly, septic emboli from endocarditis and others (3,4,5,6,7,8,9,10)
  • Usually mixed flora with predominance of anaerobes (1)
  • Oral flora anaerobes (60–75% of cases):
    • Peptostreptococcus
    • Prevotella
    • Fusobacterium
    • Bacteroides sp.
  • Aerobes (10–20%):
    • Staphylococcus aureus
    • Streptococcus pyogenes
    • Klebsiella sp.
    • Pseudomonas aeruginosa
    • Streptococcus milleri
  • Atypical aerobes:
    • Legionella
    • Nocardia
  • Actinomyces

Commonly Associated Conditions

  • Periodontal disease
  • Pneumonia
  • Alcoholism
  • Empyema (if necrosis of the abscess wall allows entry into pleural space) (1)
  • Tuberculosis
  • Immunocompetent patient

Immunodeficiency, pulmonary embolism, respiratory tract infection, airway obstruction,



  • Fever
  • Night sweats
  • Diaphoresis
  • Malaise
  • Anorexia
  • Weight loss
  • Chest pain/pleurisy
  • Cough with purulent, foul-smelling, putrid, sour-tasting sputum
  • Dyspnea
  • Hemoptysis

Physical Exam

  • Vital signs: Tachypnea, tachycardia
  • Lung exam:
    • Crackles
    • Wheezing
    • Dullness to percussion
    • Consolidation by auscultation
    • Cavernous breath sounds
    • Decreased breath sounds
  • Clubbing of digits

Diagnostic Tests & Interpretation


  • Complete blood count (CBC) shows leukocytosis and anemia.
  • Hypoalbuminemia
  • Sputum smear: Neutrophils, mixed bacteria
  • Sputum culture: Often grows normal respiratory flora; may help in atypical presentations
  • Blood culture: Often negative in anaerobic abscess
  • Drugs that may alter lab results: Prior antibiotics


  • CXR:
    • Lung cavity with air–fluid level
    • Consolidation with radiolucency, infiltrates, pleural effusion, mediastinal adenopathy
  • Ultrasound:
    • Color Doppler ultrasound: Great sensitivity, specificity, positive predictive value, and negative predictive value when identification of vessel signals in a pericavitary consolidation is achieved (11,12,13).
  • CT scan:
    • Defines location and extent (typical location depends on segments such as posterior segments of upper lobes or superior segments of lower lobes)
    • May detect obstructing lesion
    • May demonstrate cavitary opacities (10)
    • May show multiple thrombus of neck vessels (infectious thrombophlebitis) (14)

Diagnostic Procedures/Surgery

  • Bronchoscopy if obstruction is suspected
  • Bronchoscopic brushing
  • Bronchoalveolar lavage
  • Transthoracic needle aspiration (rarely done)
  • Percutaneous catheter-guided drainage (12,15,16,17)

Pathological Findings

  • Solitary abscess
  • Multiple abscesses
  • Cavitation with necrosis
  • Effusion/empyema

Differential Diagnosis

  • Bronchogenic carcinoma
  • Bronchiectasis
  • Empyema with bronchopulmonary fistula
  • Tuberculosis
  • Mycotic lung infections
  • Vasculitis
  • Parasitic lung infections
  • Infected pulmonary bulla
  • Wegener granulomatosis
  • Pulmonary sequestration
  • Subphrenic or hepatic abscess with perforation into a bronchus
  • Bronchogenic or parenchymal cyst
  • Aspirated foreign body



First Line

Antibiotics according to culture and sensitivity results; for presumed anaerobes, clindamycin 600 mg q6h IV followed by 300 mg q6h p.o. × 4 weeks

Second Line

  • Historically, standard therapy had been penicillin G 1 million–2 million units IV q4h until improvement, followed by 1.2 million units (750 mg) p.o. q6h × 3–4 weeks; now many relevant pathogens produce β-lactamase.
  • Cefoxitin 2.0 g IV q8h
  • Piperacillin-tazobactam 3.375 g IV q6h
  • Ticarcillin-clavulanate 3.1 g IV q6h
  • Metronidazole has not proven as effective as clindamycin but often is recommended for use as an adjunctive therapy (500 mg IV q6h).
  • Full course of therapy may be needed for 8 weeks.

Additional Treatment

General Measures

  • Postural drainage
  • Nasotracheal suctioning if needed
  • Prolonged course of antibiotics
  • Pulmonary physiotherapy
  • Bronchoscopy with selective therapeutic lavage (rarely done)
  • In general, 10% require surgical intervention, such as drainage of abscess or empyema (1).

Surgery/Other Procedures

  • Antibiotic treatment is successful in most patients; surgical options are considered when medical therapy fails (18)[B].
  • Endoscopy drainage (19)
  • Tube thoracostomy with medical failure or prohibitive operative risk (20)[B]
  • Thoracoscopy drainage (21)
  • Percutaneous catheter-guided drainage (12,15,16,17,20)
  • Pulmonary resection only if complications occur or if patient fails therapy (mortality 11–16%)

In-Patient Considerations

Initial Stabilization

Inpatient care for monitoring and treatment

Ongoing Care

Follow-Up Recommendations

Activity reduced until radiographic evidence of clearing

Patient Monitoring

Serial radiographs until resolution of cavity

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Patient Education

Pulmonary physiotherapy techniques


  • Clinical improvement with decrease in fever expected 3–4 days after starting antibiotics
  • Defervescence expected in 7–10 days
  • Prognosis depends on the underlying disease or immunosuppression (22).
  • Patients with primary abscess (otherwise healthy, typical aspiration) have cure rates of 90–95%.
  • Certain factors tend to have worse prognosis:
    • Large abscess (>6 cm)
    • Anatomic obstruction
    • Right lower lobe location
    • Certain bacteriologic species: S. aureusKlebsiellaPseudomonas
  • Overall mortality 15–20% (23)
  • Patients with secondary abscess (underlying neoplasm, obstruction, HIV) have 75% mortality.

Geriatric Considerations

Mortality higher in the elderly


  • Extension
  • Empyema
  • Massive hemoptysis
  • Pneumothorax
  • Brain abscess


1. Moreira Jda S, Camargo Jde J, Felicetti JC, et al. Lung abscess: analysis of 252 consecutive cases diagnosed between 1968 and 2004. J Bras Pneumol. 2006;32:136–43.

2. Hirshberg B, Sklair-Levi M, Nir-Paz R, et al. Factors predicting mortality of patients with lung abscess. Chest. 1999;115:746–50.

3. Agrafiotis M, Siempos II, Falagas ME. Infections Related to Airway Stenting: A Systematic Review. Respiration. 2009.

4. Munthe-Fog L, Hummelshøj T, Honoré C, et al. Immunodeficiency associated with FCN3 mutation and ficolin-3 deficiency. N Engl J Med. 2009;360:2637–44.

5. Aylk S, Qakan A, Aslankara N, et al. Tuberculous abscess on the chest wall. Monaldi Arch Chest Dis. 2009;71:39–42.

6. Chirinos JA, Garcia J, Alcaide ML, et al. Septic thrombophlebitis: diagnosis and management. Am J Cardiovasc Drugs. 2006;6:9–14.

7. Hirshberg B, Oppenheim-Eden A, Pizov R, et al. Recovery from blast lung injury: one-year follow-up. Chest. 1999;116:1683–8.

8. Hsu PS, Lee SC, Tzao C, et al. Bronchoperitoneal fistula from a lung abscess. Respirology. 2008.

9. Mawdsley JE, Maleki N, Benjamin E, et al. Oesophageal perforation with asymptomatic lung abscess formation. Lancet. 2006;368:2104.

10. O’Brien JD, Ettinger NA. Nephrobronchial fistula and lung abscess resulting from nephrolithiasis and pyelonephritis. Chest. 1995;108:1166–8.

11. Chen HJ, Yu YH, Tu CY, et al. Ultrasound in Peripheral Pulmonary Air-Fluid Lesions: Color Doppler Imaging as an Aid in Differentiating Empyema and Abscess. Chest. 2009.

12. Stavas J, vanSonnenberg E, Casola G, et al. Percutaneous drainage of infected and noninfected thoracic fluid collections. J Thorac Imaging. 1987;2:80–7.

13. Simeone JF, Mueller PR, vanSonnenberg E. The uses of diagnostic ultrasound in the thorax. Clin Chest Med. 1984;5:281–90.

14. Velagapudi P, Turagam M, Are C, et al. “A forgotten disease”: a case of lemierre syndrome. ScientificWorldJournal. 2009;9:331–2.

15. Chen CH, Chen W, Chen HJ, et al. Transthoracic Ultrasonography in Predicting the Outcome of Small-bore Catheter Drainage in Empyemas or Complicated Parapneumonic Effusions. Ultrasound Med Biol.2009.

16. vanSonnenberg E, D’Agostino HB, Sanchez RB, et al. Percutaneous abscess drainage. Radiology. 1992;184:27–9.

17. vanSonnenberg E, D’Agostino HB, Casola G, et al. Lung abscess: CT-guided drainage. Radiology. 1991;178:347–51.

18. Mansharamani N, Koziel H. Chronic lung sepsis: Lung abscess, bronchiectasis, and empyema. Curr Opin Pulmon Med. 2003;9:181–5.

19. Herth F, Ernst A, Becker HD. Endoscopic drainage of lung abscesses: technique and outcome. Chest. 2005;127:1378–81.

20. Wali SO, Shugaeri A, Samman YS, et al. Percutaneous drainage of pyogenic lung abscess. Scand J Infect Dis. 2002;34:673–9.

21. Nagasawa KK, Johnson SM et al. Thoracoscopic treatment of pediatric lung abscesses. J Pediatr Surg. 2010;45:574–8.

22. Hsieh MJ, Liu YH, Chao YK, et al. Risk factors in surgical management of thoracic empyema in elderly patients. ANZ J Surg. 2008;78:445–8.

23. Lin JN, Tsai YS, Lai CH, et al. Risk Factors for Mortality of Bacteremic Patients in the Emergency Department. Acad Emerg Med. 2009.

Additional Reading

See Also (Topic, Algorithm, Electronic Media Element)

Pneumonia, Bacterial



513.0 Abscess of lung


73452002 abscess of lung (disorder)

Clinical Pearls

  • Bacteria are carried to the dependent portions of the lung, with the posterior segment of the right upper lobe being the most common location for abscess.
  • Percutaneous drainage and surgical resection could be considered treatment options when medical therapy fails. Endoscopic drainage techniques show promise as an alternative (19)[B].
  • Lemierre syndrome is a complication of Fusobacterium necrophorum oropharyngeal infection (usually pharyngitis). The infection extends to the internal jugular vein, causing thrombophlebitis. The thrombophlebitis, in turn, produces septic emboli, including emboli that produce lung abscess or pneumonia (6).

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