Aspergillus is a type of fungus that causes aspergillosis, an infection of the lungs that is more common in people with asthma and cystic fibrosis. (It's not entirely understood why it is more common, but it is thought to be related to altered immunity.)
People also can be allergic to aspergillus and, even if they have healthy immune systems, the allergic reaction causes a condition called allergic bronchopulmonary aspergillosis, (ABPA). ABPA occurs in up to 15% of people with cystic fibrosis, and is most common in teenagers and young adults.
Why ABPA Is a Problem
Allergic reactions cause swelling and irritation of tissues called inflammation. Since ABPA is an allergic response to aspergillus in the airway, the airway becomes inflamed. Eventually, if ABPA is not treated, the inflammation causes permanent damage to the lungs called bronchiectasis.
Symptoms of ABPA
The symptoms of APBA are:
- Shortness of breath, at rest or with exercise
- Increase in mucus
- Decrease in lung function
All of these are symptoms that commonly occur in people with cystic fibrosis anyway, so how can you tell if ABPA is the cause? You can’t tell just by symptoms -- testing will need to be done to diagnose ABPA. But, if you are experiencing an increase in any of these symptoms or general worsening of lung function without an identifiable reason, ABPA may be the culprit.
If your health care provider suspects ABPA, he will order blood tests and skin testing to see if you are allergic to aspergillus. He may also order a chest x-ray to look for structural changes in your lungs.
ABPA is usually treated with two different medications:
- Corticosteroids, such as prednisone, are prescribed to reduce inflammation in the airways.
- An antifungal, such as itraconazole, may be prescribed to help kill some of the aspergillus in the airway.
Omalizumab, a humanized monoclonal antibody against IgE, is a new additional treatment that could help children with CF and ABPA. More research is needed, however.
Reducing Your Risk
One thing you can do to decrease your chances of getting ABPA is to minimize your exposure to aspergillus. Although it’s impossible to eliminate exposure completely, there are some things you can do to reduce the amount of aspergillus in your environment.
Avoid damp places where fungus is more likely to grow: Check your home for plumbing leaks or collections of condensation. Always fix leaks as soon as you discover them.
Keep your home as dust-free as possible: Aspergillus is frequently found in household dust. Air conditioning ducts and fans are common places for dust to hide, so be sure to include them in your dusting routine. Dust is very hard to get out of carpets, so you may want to opt for tile or hard-wood floors instead.
Dust-proof your bedding: Aspergillus has been found in large amounts in pillows, especially pillows that have been in use for more than a year. Use hypoallergenic pillow and mattress covers, and replace your pillows every few months. Stuffed toys can also collect dust, so it’s best to avoid them if possible. If your child does have stuffed toys, be sure to wash and thoroughly dry them often.
HEPA Filtration: High efficiency particulate air (HEPA) filters are designed to remove very small particles from the air. HEPA filters are found in some vacuum cleaners and air purification systems. If you do decide to use HEPA filtration, be sure to purchase a true HEPA product. In order to receive a HEPA rating, a filter must remove 99.97% of airborne particles 0.3 micrometers in diameter. Products that don’t meet these requirements may claim they are “HEPA-like”, “99% HEPA” or something equally misleading.
Amchentsev, A., Kurugundla, N., and Saleh, A.G. “Aspergillus-Related Lung Disease”. Respiratory Medicine CME. Volume 1, Issue 3, 2008, Pages 205-215.