Pulmonary actinomycosis

Definition

Pulmonary actinomycosis is a rare bacterial lung infection.

Alternative Names

Actinomycosis - pulmonary

Causes, incidence, and risk factors

Pulmonary actinomycosis is caused by a species of bacteria 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 lung infections caused by actinomycosis.

The disease is rare in the U.S., with only about 100 confirmed cases per year. It may occur at any age, but most patients are 30 - 60 years old. Men get this infection more often than women do.

Symptoms

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

Symptoms include:

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

Signs and tests

Tests that may be done include:

• Bronchoscopy with culture
• Complete blood count (CBC)
• Chest x-ray
• Chest CT scan
• Lung biopsy
• Modified AFB smear of sputum
• Sputum culture
• Sputum Gram stain
• Thoracentesis with culture
• Tissue culture
• Tissue and fluid analysis

Treatment

The goal of treatment is to cure the infection. However, many patients take a long time to get better. To be cured, you may need to receive penicillin through a vein (intravenously) for 4 - 6 weeks, followed by several months of penicillin by mouth. Some people need up to 18 months of treatment.

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

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

Support Groups

Expectations (prognosis)

Most people get better after treatment with antibiotics.

Complications

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

Calling your health care provider

Call your health care provider if:

• You have symptoms of pulmonary actinomycosis
• Your symptoms get worse or do not improve with treatment
• You develop new symptoms

Prevention

Good dental hygiene may help reduce your risk of getting actinomycosis.

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References

Brook I. Actinomycosis. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 350.