A 38Year Old Man Presents With A Six Week History Of Dyspnoea and Wheezing

A 38 year old man presents with history of difficulty breathing and wheezing that has started about six weeks back, For 2 weeks he has also developed cough productive of yellow sputum and fever. There is no history of night sweats.
The patient has a past history of asthma and recurrent atopic symptoms.

A Chest X ray done as a part of diagnostic workup is shown below:

X ray findings show diffuse peri-hilar infiltrates.

On blood workup there was an eosinophillia and the sputum culture was negative.

Based on the above history and investigations for is the most likely diagnosis?

Allergic bronchopulmonary aspergillosis

Case Discussion:

Allergic bronchopulmonary aspergillosis (ABPA) is at one end of the spectrum of disease caused by pulmonary aspergillosis and can be classified as an eosinophillic lung disease.

Epidemiology:

This entity is seen mostly in patients with longstanding asthma, and only occasionally in patients with cystic fibrosis.  Only rarely does it appear in patients with no other identifiable pulmonary illness  

In general patients are young and are diagnosed before the age of 40 years 

Clinical Presentation:

Clinically, patients have atopic symptoms (especially asthma) and present with recurrent chest infection. They may expectorate orange-colored mucous plugs.

A clinical staging system has been developed

• stage I: acute
• stage II: remission
• stage III: recurrent exacerbation
• stage IV: steroid-dependent asthma
• stage V: pulmonary fibrosis

Laboratory findings include:

• elevated Aspergillus specific IgE
• elevated precipitating IgG against Aspergillus
• peripheral eosinophilia
• positive skin test

Major and minor criteria have also been established 

• major criteria
  • clinical
    • asthma
  • radiographic features
    • pulmonary opacities (transient or chronic)
    • central bronchiectasis
  • immune system
    • blood eosinophilia
    • immediate skin reactivity to Aspergillus antigen (elevated IgG and/or IgE against A.fumigatus)
    • increased serum IgE (>1000 IU/ml)
• minor criteria
  • fungal elements in sputum
  • expectoration of brown plugs / flecks
  • delayed skin reactivity to fungal antigens

Pathology:

Allergic bronchopulmonary aspergillosis (ABPA) is the result of hypersensitivity towardsAspergillus spp which grows within the lumen of the bronchi, without invasion. The hypersensitivity initially causes bronchospasm and bronchial wall oedema, which is IgE-mediated. 

Radiograpic Features:

Plain Film

Early in the disease chest x-rays will appear normal, or only demonstrate changes of asthma. Transient patchy areas of consolidation may be evident representing eosinophillic pneumonai. 

Eventually bronchiectasis may be evident. Mucoid impaction in dilated bronchi can appear mass-like or sausage shaped or branching opacities.

Treatment and Prognosis:

Treatment of ABPA is difficult due to the ubiquity of Aspergillus in the environment. The main focus of treatment revolves around ⁸: 

• managing asthma
• limiting/controlling exacerbations: corticosteroid play a major role
• eradicating Aspergillus from the airway: anti-fungals, e.g. Ketoconazole
• preventing late complications, e.g. severe bronchiectasis, fibrosis.

Many patients are successfully managed after diagnosis and never progress to stage IV or V. In stages I to III prognosis is excellent, whereas stage V has a high 5 year mortality from respiratory failure ⁹.