Lung Abscess Clinical Presentation

Updated: Sep 25, 2020
  • Author: Nader Kamangar, MD, FACP, FCCP, FCCM; Chief Editor: Guy W Soo Hoo, MD, MPH  more...
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Symptoms depend on whether the abscess is caused by anaerobic or other bacterial infection. A lung abscess may be asymptomatic in a small proportion of patients in the early stages. Typical symptoms are below.

Anaerobic infection in lung abscess

Patients often present with indolent symptoms that evolve over a period of weeks to months. The usual symptoms are fever, cough with sputum production, night sweats, anorexia, and weight loss. The expectorated sputum characteristically is foul smelling and bad tasting. Patients may develop hemoptysis or pleurisy

Other pathogens in lung abscess

These patients generally present with conditions that are more acute in nature and are usually treated while they have bacterial pneumonia. Cavitation occurs subsequently as parenchymal necrosis ensues. Abscesses from fungi, Nocardia species, and Mycobacteria species tend to have an indolent course and gradually progressive symptoms.


Physical Examination

The findings on physical examination of a patient with lung abscess are variable. Physical findings may be secondary to associated conditions such as underlying pneumonia or pleural effusion. The physical examination findings may also vary depending on the organisms involved, the severity and extent of the disease, and the patient's health status and comorbidities.

Patients with lung abscesses may have low-grade fever in anaerobic infections and temperatures higher than 38.5°C in other infections.

Generally, patients with in lung abscess have evidence of gingivitis and/or periodontal disease.

Clinical findings of concomitant consolidation may be present (eg, decreased breath sounds, dullness to percussion, bronchial breath sounds, coarse inspiratory crackles).

The amphoric or cavernous breath sounds are only rarely elicited in modern practice.

Evidence of pleural friction rub and signs of associated pleural effusion, empyema, and pyopneumothorax may be present. Signs include dullness to percussion, contralateral shift of the mediastinum, and absent breath sounds over the effusion.

Digital clubbing may develop rapidly.



Complications of pulmonary abscess include the following:

  • Rupture into pleural space causing empyema

  • Pleural fibrosis

  • Trapped lung

  • Respiratory failure

  • Bronchopleural fistula

  • Pleural cutaneous fistula

In a patient with coexisting empyema and lung abscess, draining the empyema while continuing prolonged antibiotic therapy is often necessary.