What is the definition of Pulmonary Actinomycosis?

Pulmonary actinomycosis is a rare lung infection caused by bacteria.

What are the alternative names for Pulmonary Actinomycosis?

Actinomycosis - pulmonary; Actinomycosis - thoracic

What are the causes for Pulmonary Actinomycosis?

Pulmonary actinomycosis is caused by certain bacteria normally found in the mouth and gastrointestinal tract. The bacteria often do not cause harm. But poor dental hygiene and tooth abscess can increase your risk for lung infections caused by these bacteria.

People with the following health problems also have a higher chance of developing the infection:

  • Alcohol use
  • Scars on the lungs (bronchiectasis)
  • COPD

The disease is rare in the United States. It may occur at any age, but is most common in people 30 to 60 years old. Men get this infection more often than women.

What are the symptoms for Pulmonary Actinomycosis?

The infection often comes on slowly. It may be weeks or months before diagnosis is confirmed.

Symptoms may include any of the following:

  • Chest pain when taking a deep breath
  • Cough with phlegm (sputum)
  • Fever
  • Shortness of breath
  • Unintentional weight loss
  • Lethargy
  • Night sweats (uncommon)

What are the current treatments for Pulmonary Actinomycosis?

The goal of treatment is to cure the infection. It may take a long time to get better. To be cured, you may need to receive the antibiotic penicillin through a vein (intravenously) for 2 to 6 weeks. Then you need to take penicillin by mouth for a long period. Some people need up to 18 months of antibiotic treatment.

If you cannot take penicillin, your provider will prescribe other antibiotics.

Surgery may be needed to drain fluid from the lungs and control the infection.

What is the outlook (prognosis) for Pulmonary Actinomycosis?

Most people get better after treatment with antibiotics.

What are the possible complications for Pulmonary Actinomycosis?

Complications may include:

  • Brain abscess
  • Destruction of parts of the lungs
  • COPD
  • Meningitis
  • Osteomyelitis (bone infection)

When should I contact a medical professional for Pulmonary Actinomycosis?

Call your provider if:

  • You have symptoms of pulmonary actinomycosis
  • Your symptoms get worse or do not improve with treatment
  • You develop new symptoms
  • You have a fever of 101°F (38.3°C) or higher

How do I prevent Pulmonary Actinomycosis?

Good dental hygiene may help reduce your risk for actinomycosis.

Respiratory system
Gram stain of tissue biopsy


Brook I. Actinomycosis. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 313.

Russo TA. Agents of actinomycosis. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 254.

  • Journal: BMJ case reports
  • Published —
When sarcoidosis mimics immunodeficiency.
  • Journal: Journal of infection in developing countries
  • Published —
Unusual presentations of actinomycosis: a case series and literature review.

There are no recent clinical trials available for this condition. Please check back because new trials are being conducted frequently.