Allergic Bronchopulmonary Aspergillosis

Allergic bronchopulmonary aspergillosis (abbreviated to ABPA) is a disorder typified by an exaggerated immune response to a type of fungus; most commonly Aspergillus fumigatus. The condition is most common in patients already suffering from asthma or cystic fibrosis.

Causes

ABPA usually occurs as a complication of a pre-existing chronic lung disease, often asthma or cystic fibrosis.

The fungus A. fumigatus is highly prevalent in nature; particularly in soil environments.

Disease pathway

Following inhalation, spores of the fungus inhabit the mucus present in the host’s airway. Those sensitive to the fungus will develop an allergic reaction.

Inflammation of the airway ensues and may result in:

·         Blockage of the airway;

·         Inflammation of air sacs in the lungs (alveoli), impeding transfer of oxygen and carbon dioxide between bloodstream and air;

·         Permanent dilation of the central airway (bronchiectasis); and

·         Scarring of the lungs.

Symptoms and diagnosis

The earliest symptoms of allergic bronchopulmonary aspergillosis are usually progressive and resemble those of asthma, such as wheezing and shortness of breath. Brownish flecks may be visible in phlegm that is coughed up.

Chest x-rays may indicate widened airways, often congested with mucus. Presence of the fungus itself can be determined by examining the mucus under a microscope.

Treatment

Due to the ubiquity of A. fumigatus in the natural environment, the fungus is near-impossible to avoid. Anti-asthma drugs are usually used to treat the allergic bronchopulmonary aspergillosis.

The anti-asthma drugs also serve to open up the airways, helping the patient to cough up congested mucus and therefore eliminate the fungus.