Aspergillosis is an infection, usually of the lungs, caused by the fungus Aspergillus.
- A ball of fungus fibers, blood clots, and white blood cells may form in the lungs or sinuses.
- People may have no symptoms or may cough up blood or have a fever, chest pain, and difficulty breathing.
- If fungi spread to the liver or kidneys, these organs may malfunction.
- Diagnosis usually involves an x-ray or computed tomography and, if possible, culture of a sample of infected material.
- Antifungal drugs are used, and sometimes surgery is needed to remove the fungal balls.
(See also Overview of Fungal Infections.)
Aspergilli are very common in the environment—indoors and out—and frequently occur in compost heaps, air vents, and airborne dust. These fungi are thus unavoidable.
Usually, aspergillosis is caused by inhaling Aspergillus spores. Most people inhale these spores every day without being affected. But if the immune system is weak, infection is more likely because aspergillosis is an opportunistic fungal infection (one that takes advantage of a weakened immune system). The immune system may be weakened by the following:
- Disorders that affect the immune system (including AIDS and some hereditary disorders)
- Drugs such as corticosteroids (if high doses are taken for a long time), cancer chemotherapy, or drugs used to prevent an organ transplant from being rejected
Aspergillosis has several forms:
- Pulmonary aspergillosis: Aspergillosis usually develops in open spaces in the body, such as cavities in the lungs caused by preexisting lung disorders. The infection may also develop in the ear canals and sinuses. In the sinuses and lungs, aspergillosis typically develops as a ball (aspergilloma) composed of a tangled mass of fungus fibers, blood clots, and white blood cells. The fungus ball gradually enlarges, destroying lung tissue in the process, but usually does not spread to other areas.
- Invasive aspergillosis: Less often, aspergillosis becomes very aggressive and rapidly spreads throughout the lungs and often through the bloodstream to the brain, heart, liver, and kidneys. This rapid spread occurs mainly in people with a very weakened immune system.
- Allergic bronchopulmonary aspergillosis: Some people who have asthma or cystic fibrosis develop a chronic allergic reaction with cough, wheezing, and fever if Aspergillus colonizes the lining of their airways.
- Superficial aspergillosis: This form is uncommon. It may develop in burns, under bandages, after damage to the eye, or in the sinuses, mouth, nose, or ear canal.
Symptoms of Aspergillosis
A fungus ball in the lungs may cause no symptoms and may be discovered only when a chest x-ray is taken for other reasons. Or it may cause repeated coughing up of blood and, rarely, severe, even fatal bleeding.
A rapidly invasive infection in the lungs often causes cough, fever, chest pain, and difficulty breathing. Without treatment, this form of invasive aspergillosis is fatal.
Aspergillosis that spreads to other organs makes people very ill. Symptoms include fever, chills, shock, delirium, and blood clots. Kidney failure, liver failure (causing jaundice), and breathing difficulties may develop. Death can occur quickly.
Aspergillosis of the ear canal causes itching and occasionally pain. Fluid draining overnight from the ear may leave a stain on the pillow.
Aspergillosis of the sinuses causes a feeling of congestion and sometimes pain or discharge or bleeding from the nose.
Diagnosis of Aspergillosis
- Culture, examination, and analysis of a sample of infected material
Doctors suspect aspergillosis based on symptoms. An x-ray or computed tomography (CT) of the infected area also provides clues for making the diagnosis.
To identify the fungus, doctors usually need to send a sample of infected material to a laboratory to grow (culture), examine, and analyze. A viewing tube (bronchoscope or rhinoscope) may be used to obtain this material from the lungs or sinuses. Sometimes a biopsy is necessary to obtain a sample.
Treatment of Aspergillosis
- Antifungal drugs
- Sometimes surgery to remove fungi
Aspergillosis that affects only a sinus or a single area in the lung requires treatment but does not pose an immediate danger because it progresses slowly. However, if the infection is widespread or if people appear seriously ill or have a weakened immune system, treatment is started immediately.
Invasive aspergillosis is treated with antifungal drugs, such as voriconazole, isavuconazole, or sometimes posaconazole or itraconazole. However, some forms of Aspergillus do not respond to these drugs and may need to be treated with amphotericin B or with a combination of drugs. Any condition that is weakening the immune system should be corrected if possible. For example, doctors may advise people who are taking corticosteroids, which suppress the immune system, to stop.
Aspergillosis in the ear canal is treated by scraping out the fungus and applying drops of antifungal drugs. Collections of fungi in the sinuses must usually be removed surgically.
Fungus balls in the lungs (aspergillomas) usually do not require treatment with drugs and do not usually respond to drugs. If these balls cause bleeding (causing people to cough up blood) or other symptoms, they may need to be removed surgically. Surgery cures the infection but is often risky because many of these people have other disorders.
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