Pulmonary aspergillosis - allergic bronchopulmonary type

Definition

Pulmonary aspergillosis is an allergic reaction to a fungus called aspergillus, which causes inflammation of the airways and air sacs of the lungs.

Alternative Names

Aspergillosis - allergic bronchopulmonary; Allergic bronchopulmonary aspergillosis; ABPA

Causes, incidence, and risk factors

The aspergillus fungus is common. It can grow on dead leaves, stored grain, bird droppings, compost stacks, and other decaying vegetation.

Although most people are frequently exposed to aspergillus, infections caused by it are rare in people with a normal immune system. These rare infections include pneumonia and fungus ball (aspergilloma).

Some people, however, have an allergic reaction (hypersensitivity) to this fungus, which is called allergic bronchopulmonary aspergillosis (ABPA). It is characterized by inflammation of the airways (bronchi) or air sacs (alveoli). The disease may mimic asthma or pneumonia, and, in fact, most patients with ABPA have asthma as well.

Patients with asthma or cystic fibrosis are at highest risk for allergic aspergillosis.

Symptoms

• Cough may produce brownish plugs or bloody sputum
• Fever
• Generalized weakness
• Wheezing
• Worsening symptoms of asthma

Signs and tests

• Aspergillus antigen skin test
• Bronchoscopy and transbronchial biopsy
• CBC with peripheral eosinophil (a type of white blood cell) count
• Chest x-ray
• CT scan - chest
• Lung biopsy (rare)
• Serum aspergillus antibodies
• Serum IgG and IgE antibodies
• Sputum stain and culture for fungus

Treatment

Allergic aspergillosis is treated with steroids such as prednisone. The antifungal antibiotic itraconazole can also be helpful. People with asthma should also continue their usual treatments.

Expectations (prognosis)

People usually get better with treatment, over time. Relapses requiring repeat treatment are common.

Complications

• Bronchiectasis (permanent scarring of the small sacs in the lungs)
• Mucous plugs
• Permanent airway obstruction
• Respiratory failure

Calling your health care provider

Call your health care provider if you have symptoms of this disorder.

Call your health care provider if breathing becomes more difficult. Severe breathing difficulty is an emergency.

Prevention

People at higher risk (those with asthma, cystic fibrosis, etc.) should try to avoid environments where this fungus is found.

References