Nocardia infection develops when you breathe in (inhale) the bacteria. The infection causes pneumonia-like symptoms. The infection can spread to any part of the body.

People with a weak immune system are at a high risk for nocardia infection. This includes people who have:

• Been taking steroids or other medicines that weaken the immune system for a long time
• Cushing disease
• An organ transplant
• HIV/AIDS
• Lymphoma (a type of cancer)

Other people at risk include those with long-term (chronic) lung problems related to smoking, emphysema, or tuberculosis.

Pulmonary nocardiosis mainly affects the lungs. But, nocardiosis can also spread to other organs in the body. Common symptoms may include:

ENTIRE BODY

• Fever (comes and goes)
• General ill feeling (malaise)
• Night sweats

GASTROINTESTINAL SYSTEM

• Nausea
• Liver and spleen swelling (hepatosplenomegaly)
• Loss of appetite
• Unintentional weight loss
• Vomiting

LUNGS AND AIRWAYS

• Breathing difficulty
• Chest pain not due to heart problems
• Coughing up blood or mucus
• Rapid breathing
• Shortness of breath

MUSCLES AND JOINTS

• Joint pain

NERVOUS SYSTEM

• Change in mental state
• Confusion
• Dizziness
• Headache
• Seizures
• Changes in vision

SKIN

• Skin rashes or lumps
• Skin sores (abscesses)
• Swollen lymph nodes

Your health care provider will examine you and listen to your lungs using a stethoscope. You may have abnormal lung sounds, called crackles. Tests that may be done include:

• Bronchoalveolar lavage -- fluid is sent for stain and culture, which is taken by bronchoscopy
• Chest x-ray
• Chest CT
• MRI scan of the chest
• Pleural fluid culture and stain
• Sputum stain and culture

The goal of treatment is to control the infection. Antibiotics are used, but it may take a while to get better. Your provider will tell you how long you need to take the medicines. This may be for up to a year.

Surgery may be needed to remove or drain infected areas.

Your provider may tell you to stop taking any medicines that weaken your immune system. Never stop taking any medicine before talking to your provider first.

The outcome is often good when the condition is diagnosed and treated quickly.

The outcome is poor when the infection:

• Spreads outside the lung.
• Treatment is delayed.
• The person has a serious disease that leads to or requires long-term suppression of the immune system.

Complications of pulmonary nocardiosis may include:

• Brain abscesses
• Skin infections
• Kidney infections

Contact your provider if you have symptoms of this disorder. Early diagnosis and treatment may improve the chance of a good outcome.

Be careful when using corticosteroids. Use these medicines sparingly, in the lowest effective doses and for the shortest periods of time possible.

Some people with a weak immune system may need to take antibiotics for long periods of time or indefinitely to prevent the infection from returning.

Nocardiosis - pulmonary; Mycetoma; Nocardia

Dockrell DH, Ho A, Gordon SB. Community-acquired pneumonia. In: Broaddus VC, Ernst JD, King Jr TE, et al, eds. Murray and Nadel's Textbook of Respiratory Medicine. 7th ed. Philadelphia, PA: Elsevier; 2022:chap 46.

Southwick FS. Nocardiosis. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 314. 

Updated by: Denis Hadjiliadis, MD, MHS, Paul F. Harron Jr. Professor of Medicine, Pulmonary, Allergy, and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.