Allergic Bronchopulmonary Aspergillosis (ABPA)
(Aspergillosis)
Definition |
Causes |
Risk Factors |
Symptoms |
Diagnosis |
Treatment |
Prevention |
Organizations
Definition
Allergic bronchopulmonary aspergillosis (ABPA; also called aspergillosis) is an allergic lung disorder. It is related to the fungus Aspergillus fumigatus (AF). Aspergillosis can also occur as:
- A lung infection that can spread to other parts of the body. This is more common in patients with suppressed immune systems.
- A growth of fungus (aspergilloma) in a lung cavity that has healed from a previous lung disease or infection.
Causes
ABPA is caused by an allergic reaction to inhaled AF. AF is a common fungus. It grows and flourishes in decaying vegetation, soil, certain foods, dust, and water. The allergic reaction worsens respiratory symptoms in people with asthma or cystic fibrosis. The inhaled AF colonizes mucus in the lungs, causing:
- Sensitization to AF.
- Recurring allergic inflammation of the lungs.
- Packing of the aveoli (tiny air sacs in the lungs) with eosinophils. Eosinophils are a type of white blood cell involved in certain allergic reactions and infections with parasites.
Risk Factors
A risk factor is something that increases your chances of getting a disease or condition. Risk factors for ABPA include:
Symptoms
Symptoms of ABPA are usually those of progressive asthma. These include:
- Shortness of breath
- Wheezing
As ABPA progresses, other symptoms may occur. These include:
- Production of thick, brownish, and/or bloody sputum
- Low-grade fever
In severe, long-term cases, ABPA can cause:
- Bronchiectasis widening of areas of the bronchus (the windpipe or trachea), usually caused by inflammation
- Scarring of lungs
Diagnosis
The doctor will ask about your symptoms and medical history and perform a physical exam. Tests may include:
- Chest x-ray
- Sputum tests checking of sputum for:
- Presence of AF
- High levels of eosinophils
- Blood tests to detect:
- High levels of eosinophils
- Antibodies suggesting an allergic reaction to AF
- Skin prick tests small amounts of AF are placed in the skin to check for allergic sensitivity
- Pulmonary function tests (PFTs) used to monitor breathing capacity of the lungs
Since ABPA can appear quite similar to non-ABPA induced asthma, it is often difficult to determine to what extent ABPA is contributing to your symptoms. Therefore, ABPA is usually not diagnosed unless several repeated tests for ABPA are positive over a number of months or years.
Treatment
The goals of treatment include:
- Suppressing the allergic reaction to AF
- Minimizing lung inflammation
- Preventing AF from colonizing the lungs
ABPA is usually treated with two medications:
- Prednisone an oral corticosteroid medication
- Itraconazole (Sporanox) an anti-fungal drug
Prevention
Avoiding exposure to AF is the best way to prevent ABPA. However, this is difficult, because AF is so prevalent in the environment. Guidelines to help prevent exposure to AF include:
- Avoiding areas with:
- Decaying vegetation
- Standing water
- Keeping one's home as dust free as possible
- Remaining in air-filtered, air-conditioned environments whenever possible
Measures to avoid symptoms and prevent permanent lung damage caused by ABPA include:
- Ongoing testing and monitoring of ABPA
- Early and continued treatment with medication for the disease
Organizations
National Institute of Diabetes & Digestive & Kidney Diseases
http://www.niddk.nih.gov
American Lung Association.
http://www.lungusa.org
Center for Disease Control and Prevention
http://www.cdc.gov
SOURCES:
Mayo Foundation for Medical Education and Research
National Institute of Diabetes & Digestive & Kidney Diseases
The Merck Manual of Medical Information. Simon and Schuster, Inc., 2000.
Last reviewed June 2002 by Medical Review Board
