What is aspergillosis?
Aspergillosis is an infection or allergic reaction
caused by various kinds of mold (a type of fungus). Mold is often found outdoors
on plants, soil, or rotting vegetable matter. Mold can also grow indoors on
household dust, food items such as ground spices, and building materials.
Aspergillus fumigatus is the type of mold that is most likely to cause
aspergillosis in certain people when they inhale (breathe in) its spores.
Who gets aspergillosis?
Exposure to Aspergillus is not likely to cause
problems in people whose immune systems are healthy. However, people with
chronic lung problems or people with weak immune systems may be at greater risk
for developing the infection. People with weakened immune systems include those
people taking chemotherapy or those who have had organ transplants.
Is there more than one type of aspergillosis?
There are several types of aspergillosis.
Pulmonary aspergillosis is most likely to develop
in people who have chronic lung disorders or damaged lungs. These people are
likely to have abnormal spaces in their lungs where the fungus can grow. The
fungus can also infect sinuses and ear canals. The mold spores can colonize
(grow) inside lung cavities that developed as a result of chronic diseases, such
tuberculosis, emphysema, or advanced sarcoidosis. The fibers of fungus might
form a lump by combining with white blood cells and blood clots. This lump or
ball of fungus is called an aspergilloma or mycetoma. In some cases, a fungus
ball may be present in other organs of the body.
Invasive aspergillosis, the most severe type,
occurs when the infection travels from the lungs into the bloodstream. Other
organs, such as the kidneys, liver, skin or brain, may become infected. This is
a very serious condition that may result in death if not treated. People with
weakened immune systems are more susceptible to invasive aspergillosis. Other
risk factors include a low white blood cell count, long-term use of
corticosteroid drugs, or hospitalization.
Allergic bronchopulmonary aspergillosis (ABPA)
is an allergic reaction that happens to some people after exposure to
Aspergillus fungus. The fungus can cause swelling in the lungs and air
passages. ABPA is more common in people with cystic fibrosis or asthma because
they tend to have more mucus in their airways. Although it is unclear exactly
why the allergic reaction occurs, the mucus in their airways may provide a good
environment for the mold to grow. Unfortunately, the allergic reaction may
produce symptoms similar to those associated with asthma or cystic fibrosis,
including wheezing, coughing and difficulty with breathing.
What causes aspergillosis?
In most cases, aspergillosis is caused by a type of
mold called Aspergillus fumigatus. Aspergillus mold can often be
found on dead leaves, compost piles and other decaying vegetable matter, stored
grain, and even foods and spices. The mold spores may be carried indoors on
shoes and clothing and can grow on carpeting. Window unit air conditioners are
susceptible to mold growth if filters are not kept clean, and water does not
drain properly from the unit. Sites where buildings are being torn down or
renovated may be contaminated with mold spores.
What are the symptoms of aspergillosis?
Symptoms can range from mild to severe, depending on the type of aspergillosis.
Pulmonary aspergillosis might not cause any symptoms,
especially in the early stages. If the disease progresses, symptoms may include:
- Coughing, sometimes accompanied by mucus or blood
- Chest pain
- Difficulty breathing
Symptoms of invasive aspergillosis may include:
- Breathing difficulties, such as shortness of breath
- Kidney or liver failure
- Bloody cough or massive bleeding from the lungs
Allergic bronchopulmonary aspergillosis may cause:
- Coughing accompanied by mucus or blood
- Wheezing or worsening of asthma
- Increased mucus or sputum secretions
- Inability to tolerate exercise or asthma brought on by exercise
Many patients with asthma or cystic fibrosis already
experience respiratory symptoms similar to those caused by an allergic reaction,
so it may be difficult to detect ABPA in these situations. Sometimes, a
worsening of symptoms such as coughing and wheezing is the only sign that the
person is experiencing an allergic reaction.
If the allergic reaction recurs over time, and the
lungs become inflamed repeatedly, damage to the lungs and central airways can
occur. Recurrent allergic reactions may cause scarring of lung tissue and
widening of the central airways, a condition known as bronchiectasis.
How common is aspergillosis?
It is estimated that up to 10% of people with cystic fibrosis or asthma experience an allergic reaction to aspergillus.
ABPA is more frequent in young adults than in children.
How can aspergillosis be prevented?
Due to the prevalence of aspergillus mold in
the environment, it is very difficult to avoid exposure. It is best to avoid
locations with excessive amounts of dust or mold, such as construction sites or
compost piles. People with weakened immune systems or mold allergies should
avoid activities such as gardening or lawn mowing. If exposure to airborne dust
or mold is likely, considering wearing a face mask or N95 mask. In some cases,
your doctor might recommend the use of an antifungal medicine to prevent infection.
How is aspergillosis diagnosed?
Your doctor will probably ask you about your medical
history, including the type and duration of your symptoms and whether you have a
cough or a fever. It may be difficult to diagnose the condition, because
symptoms may resemble those of other diseases.
Some of the diagnostic tests that may be required include:
- Skin and blood tests—These tests are useful to diagnose ABPA,
especially in cases where the patient has asthma or cystic fibrosis. The
doctor or technician injects a small quantity of aspergillus antigen into
the skin, usually the lower arm. A small red bump at or near the site will
show that you have an allergic reaction. In addition, a sample of your blood
might be analyzed to see if certain antibodies are present that indicate an allergic reaction.
- Imaging tests—A chest X-ray or computerized tomography scan (CAT
scan) may be performed to examine the lungs
- Sputum culture—A sample of sputum might be stained (dyed) and
tested to see if aspergillus fungus is present.
- Biopsy—A small sample of tissue is removed from the lungs or sinuses
to diagnose invasive aspergillosis
How is aspergillosis treated?
Treatment options include oral corticosteroids, antifungal medications and surgery.
- Oral corticosteroid drugs—Solid or liquid oral medications may be
prescribed to treat allergic bronchopulmonary aspergillosis. These drugs
reduce inflammation and prevent respiratory symptoms, such as wheezing and
coughing, from getting worse. Some of the most commonly used drugs are
prednisone, prednisolone, and methylprednisolone.
- Antifungal drugs—These medications are generally used to treat
invasive pulmonary aspergillosis. Voriconazole is currently the drug of
choice because it causes fewer side effects and appears to be more effective
than other medications. Amphotericin B or itraconazole are also effective in
treating infection. Caspofungin is sometimes used in cases where the
infection is resistant to the other antifungals.
Antifungal drugs are sometimes used along with
oral corticosteroids when treating ABPA. Antifungals can cause serious side
effects, such as kidney and liver damage.
- Surgery—Surgery may be necessary in cases when aspergillomas are
present and cause serious problems, such as excessive bleeding. Antifungal
medications are usually not effective against aspergillomas, so surgery is
recommended. Embolization may be an option to block blood flow to the artery
supplying blood to the lung cavity where the fungus ball is located. This
will stop the bleeding, but it may recur later.
Aspergillosis: Fungal Infections: Merck Manual Home Edition
Allergic Bronchopulmonary Aspergillosis: Merck Manual Home Edition
Cystic Fibrosis Foundation—Allergic Bronchopulmonary Aspergillosis
Centers for Disease Control and Prevention—Aspergillosis (Aspergillus)
Review Article: Allergic bronchopulmonary aspergillosis Authors: I. Tillie-Leblond, A.B. Tonnel
University Hospital of Lille, Lille, France
© Copyright 1995-2011 The Cleveland Clinic Foundation. All rights reserved.
Can't find the health information you’re looking for?
This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 4/19/2011…#14770