Definition of Pulmonary actinomycosis:

Pulmonary actinomycosis is a rare bacterial lung infection.

Causes, incidence, and risk factors:

Pulmonary actinomycosis is caused by one of two types of bacteria -- actinomyces or propioni. These bacteria are normally found in the mouth and gastrointestinal tract, where they do not usually cause harm. However, poor dental hygiene and dental abscess can increase your risk for face, jaw, and lung infections caused by these bacteria.

Alcohol abuse, having scars on the lungs (bronchiectasis), and emphysema are all associated with actinomycosis.

Actinomycosis in the lungs causes lung cavities, lung nodules, and pleural effusions. The disease is rare and may occur at any age, but most patients are 30-60 years old. Men get this infection more often than women do.

Symptoms:

• Chest pain when taking a deep breath
• Cough with sputum
• Draining sinuses
• Fever
• Lethargy
• Night sweats
• Shortness of breath
• Weight loss

Signs and tests:

The infection often comes on slowly. It may be weeks or months a doctor makes a diagnosis.

Tests that may be done include:

• Bronchoscopy with culture
• Complete blood count
• Chest x-ray
• Chest CT scan
• Lung biopsy
• Thoracentesis with culture
• Tissue culture
• Tissue and fluid analysis

Treatment:

The goal of treatment is to control the infection. However, many patients take a long time to get better. You may need to receive penicillin through a vein (intravenously) for 4 to 6 weeks in order to be cured, followed by several months of penicillin by mouth.

If you cannot take penicillin, alternative antibiotics are available. These include tetracyclines, macrolides, or clindamycin.

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

Expectations (prognosis):

Most people get better after treatment with antibiotics.

Complications:

• Brain abscess
• Destruction of parts of the lungs
• Emphysema
• Meningitis
• Osteomyelitis

Calling your health care provider:

Call your health care provider if you have symptoms of pulmonary actinomycosis.

Also call if your symptoms get worse or do not improve with treatment, or if new symptoms develop.

Prevention:

Good dental hygiene helps prevent actinomycosis.