Nocardiosis is an infection caused by a germ called the Nocardia bacteria. Nocardia germs grow in soil or standing water all over the world. Nocardiosis usually affects your lungs or skin. But if Nocardia enters your brain or spinal cord, it can cause life-threatening problems. Fortunately, your immune system usually protects you from this bacteria.
However, if your immune system is weakened or your have certain medical conditions, you're at higher risk for infection. You can get the pulmonary (lung) version from breathing in the bacteria. Or if the bacteria gets into an open wound, you can get a primary skin (cutaneous) infection.
How common is nocardiosis?
Between 500 and 1,000 people get nocardiosis each year in the U.S. But about 6 out of every 10 people who get nocardiosis have a weakened immune system. Fortunately, with treatment you can avoid serious complications. Find out who's at risk for Nocardia infection, the symptoms, and how to prevent complications from nocardiosis.
What Causes Nocardiosis?
The group of bacteria called Nocardia causes nocardiosis infections. These bacteria live in the soil, decaying plants, and even puddles of standing water. You come in contact with the germs by just being outdoors or around dirt.
There are a few specific types of Nocardia that can cause problems:
- Nocardia asteroides
- Nocardia brasiliensis
- Nocardia caviae
- Nocardia farcinica
All of these germs can get into your body if you:
- Breathe them in
- Cut or scrape your skin
From there, the germs can infect your lungs or skin. Nocardia usually doesn't cause problems unless your immune system can't fight off infections. That's why it's called an "opportunistic" germ.
What Are the Symptoms of Nocardiosis?
Often, the signs for nocardiosis come on slowly. You may not have symptoms at first. As symptoms appear, the signs can depend on where you are infected.
Pulmonary nocardiosis
With nocardiosis in your lungs, or pulmonary nocardiosis, you may have:
- Fever and chills
- Coughing
- Sweating at night
- Feeling weak or tired
- Lack of appetite
- Unexplained weight loss
- Shortness of breath or a hard time breathingF
- Coughing up blood
- Chest pain
Nocardiosis skin infection
Nocardiosis skin infections are more common in people who have a weakened immune system. Here are three different types of skin infections.
Local infection. Nocardia can infect your skin in one area, near the cut or scrape. The infection can cause you to get:
- Bumps (nodules)
- Ulcers
- Small raised bumps that are solid (papules)
- Pus-filled bumps (pustules)
- Red swollen patches called cellulitis
- Deeper collection of pus called subcutaneous abscess
"The main issue with localized disease is that it's difficult to diagnose," says Nancy Madinger, MD, the medical director of the Clinical Microbiology Laboratory at the University of Colorado Hospital. "So, the infection slowly progresses and can cause disfigurement and scarring."
Nodular lymphangitis. Near your cut or puncture, your lymph nodes get inflamed. The inflammation can slowly move in a line up your arm or leg.
You may notice:
- Redness
- Bumps under your skin
- Red bumps
- Ulcers or sores
Mycetoma. The infection starts with one or two slow-growing bumps. They usually don't cause any discomfort. But the bumps eventually grow together. With mycetoma, you may notice that the mass:
- Becomes an abscess
- Drains a liquid with small grains
- Grows bigger on your leg or foot, but it can be anywhere
Treatment can keep Nocardia from spreading into your muscle and bone.
Nocardia in the central nervous system
If not treated, the germ can enter your bloodstream. Between 26% and 46% of Nocardia cases can spread to your central nervous system (CNS) — usually your brain.
Common signs of CNS symptoms for nocardiosis include:
Brain abscess.You can have one or multiple brain abscesses. With a brain abscess, you may have:
- Weakness on one side of your body (hemiparesis)
- Cranial nerve palsy symptoms, such as vision problems or facial numbness
- Headache
- Confusion
- Seizure
- Loss of muscle coordination (ataxia) or balance problems
Nocardial meningitis. Almost 43 in 100 people with Nocardial meningitis also had a brain abscess. If you have meningitis with a brain abscess, you can have symptoms such as:
- Fever
- Headache
- Neck stiffness
- Sensitivity to light and sound
Other Nocardia infections
Nocardiosis can happen in many other parts of your body. It's uncommon, but you can get nocardiosis in your:
- Eye, often when you've had eye surgery or a contact lens has scratched your eye before the germ got into your eye
- Bloodstream, usually comes from pulmonary nocardiosis
- Joints
- Kidneys
- Liver
- Spleen
- Adrenal glands
- Pancreas
- Thyroid gland
- Psoas muscle (a muscle deep in your lower back that connects your spine and legs)
- Spinal epidural space (the region in your spine where your doctor puts pain relief medication)
- Between the linings inside your belly (retroperitoneum)
- Urinary tract
- Prostate gland or testicles
How Is Nocardiosis Diagnosed?
Your doctor can diagnose nocardiosis by sending a tissue or fluid sample to a microbiology laboratory. The laboratory can identify the type of bacteria inside the sample.
But how the tissue or fluid sample is taken depends on where you are infected.
To diagnose nocardiosis:
- Your doctor may review your medical history and ask you questions. They may also ask about exposure to soil, water, or gardening.
- With a lung infection, your doctor may take a sputum (coughed up mucus and saliva) sample. Or they'll insert a small scope (bronchoscope) into your airway to take a small tissue sample — bronchoalveolar lavage (BAL) sampling.
- With other sites of infection, they'll carefully look at any bumps (such as on your skin) and take a small tissue or fluid sample.
The laboratory can use special stains to identify the Nocardia germ under a microscope. Or they can recover the bacteria in a culture. That means they grow larger amounts of the bacteria for testing.
The laboratory can also test your tissue or fluid sample for bacterial DNA. It's called molecular testing. They may carry out polymerase chain reaction (PCR) or whole genome sequencing to check for the bacteria.
After you get a nocardiosis diagnosis in the lungs or brain, your doctor will likely order a brain MRI and chest CT scan. These scans give more detailed images and alert your doctor about the germ spreading to those areas.
What Is the Treatment for Nocardiosis?
Your doctor will start treatment with an antibiotic. Your sample not only helps diagnose your condition but also helps your doctor know the germ "susceptibility." That means they'll know which antibiotic can destroy the Nocardia in your body.
Pulmonary nocardiosis treatment
To start with pulmonary nocardiosis treatment, your doctor may give you:
- Trimethoprim-sulfamethoxazole (Bactrim, Septra)
But if you have allergies to sulfa medications or your doctor decides to add another antibiotic, you may also get:
- Amikacin (Amikin)
- Cefotaxime (Claforan) or ceftriaxone (Rocephin)
- Dapsone (Aczone)
- Fluoroquinolones
- Imipenem (Primaxin)
- Linezolid (Zyvox)
- Meropenem (Merrem)
- Minocycline (Dynacin, Emrosi, Minocin, Solodyn, or Ximino)
- Tigecycline (Tygacil)
Depending on your symptoms, your doctor may combine medications. They may also give you the antibiotics into your vein (IV antibiotics).
Your treatment may start as IV antibiotics for the first three to six weeks. As your symptoms improve, your doctor may prescribe antibiotics to take by mouth for three to six months. But some people may take them for up to a year or more.
Nocardiosis skin infection treatment
To treat a nocardiosis skin infection, you may get:
- Trimethoprim-sulfamethoxazole (Bactrim, Septra)
- Minocycline (Dynacin, Emrosi, Minocin, Solodyn, or Ximino)
But other antibiotic options can include:
- Amoxicillin-clavulanate (Augmentin)
- Doxycycline (Acticlate, Adoxa, Atridox, Doryx, Doryx MPC, Monodox, Morgidox, Oracea, Periostat, Targadox, Vibramycin)
- Fluoroquinolones
- Macrolides
Your antibiotic treatment usually lasts three to six months. But some people may need antibiotics for up to 12 months. If you have a weakened immune system, you'll likely get antibiotics for a year.
With mycetoma, your doctor may start you out on trimethoprim-sulfamethoxazole (Bactrim, Septra). They may also add dapsone (Aczone). But if your symptoms are serious, you may get IV (into your vein) imipenem (Primaxin) alone or with amikacin (Amikin).
If you have a weakened immune system, your doctor tries to "balance treatment and minimize immunosuppression," says Madinger. They'll try not to "cause your underlying disease to flare."
What Are the Complications of Nocardiosis?
Without treatment, nocardiosis can cause serious problems. The germ can spread beyond your lungs or skin. And if your immune system is weakened, about 4 in 10 people can have life-threatening complications.
"Complications can include bacteremia and spread to the brain, skin, and, less commonly, other organs," says Madinger. Depending on the organ infected, "surgery may be required. Or treatment can be prolonged, lasting a year or even longer."
In your lungs, Nocardia can cause:
- Pneumonia
- Lung abscesses (pockets of pus)
- Respiratory failure
- In severe cases, sepsis, which is a dangerous reaction to infection that can be life-threatening
- Organ failure (if the infection spreads too far)
Skin complications, can cause:
- Ulcers (shallow sores)
- Nodules (lumps under your skin that drain if nearby lymph nodes are affected)
- Kidney infections
- Brain abscesses
"The antimicrobials used to treat Nocardia can also be difficult to tolerate," says Madinger. "The medications can lead to significant side effects, too."
You can get kidney problems (renal dysfunction), hearing loss, or stomach upset. And in some cases, you might need surgery to remove or drain the abscesses in infected areas, says Madinger.
Can Nocardiosis Be Prevented?
There are steps that can help lower your risk for nocardiosis and keep you from getting it. The first step is to know your risk. This can help you take measures to protect yourself, especially if you have a weakened immune system.
You may have a higher risk for nocardiosis if you have:
- A weakened immune system
- A medical condition such as diabetes, HIV, cancer, or connective tissue disorders
- A bone marrow or organ transplant
- Alcoholism
- Lung problems, such as pulmonary alveolar proteinosis (prevents oxygen from entering your bloodstream)
- Taken high doses of powerful steroids (drugs that help with inflammation)
- Worked outdoors and are a man (men are three times more likely to be infected)
Here are some ways you can protect yourself:
Wear gloves and a mask. This is important if you're working with dirt, dust, or soil.
Cover your skin. Wear long sleeves and pants to avoid cuts and scrapes.
Bandage any open wounds. Do this before spending time outdoors or working in the garden.
Wash your hands often. Keep your skin clean, especially after being outside or handling soil.
Treat injuries right away. Clean them with soap and water, and cover them. If the wound is deep, won't stop bleeding, or has dirt that won't come out, seek medical help.
What Questions Should I Ask My Provider?
If you have nocardiosis, here are some questions to ask your doctor:
- What type of nocardiosis do I have?
- What types of medications do I need to take?
- How long will my treatment last?
- Are there any side effects for my medications?
- Do I need to use an airway clearance device?
- Will I need follow-up visits?
- Is surgery an option? Why or why not?
- Are there any activity limits? If so, for how long?
Is nocardiosis contagious?
Nocardiosis is not contagious. You won't pick it up by being around someone else who has it. The germ doesn't spread among people.
Can nocardiosis be cured?
Yes, if nocardiosis is diagnosed early, it can be cured by using antibiotics to fight the infection. Your doctor may combine different antibiotics, too.
Takeaways
Nocardia is an uncommon bacteria that can infect you through contaminated soil or water and cause nocardiosis. It usually infects the lungs or skin of people with a weaker immune system. It can become life-threatening if it spreads to your brain. Talk to your doctor about antibiotic treatment if you're at higher risk, to avoid serious complications.
Nocardiosis FAQs
Is nocardiosis contagious?
No, nocardiosis isn't something you can catch from or spread to someone else. You can only get nocardiosis from contaminated soil or standing water.
What does a Nocardia skin infection look like?
A Nocardia skin infection usually shows up as sores or ulcers. These can look red, blistered, or crusted. You might also notice painful bumps under your skin. The bumps can appear red, purple, or darker than the surrounding area.
What is the mortality rate of nocardiosis?
The mortality rate for nocardiosis ranges from 15% to 40%. It can depend on your immune system and where your infection spreads. Your infection is more serious if it spreads to your brain or you have a weakened immune system.