Aspergillus Lung DIsease

Question 1

Definition

Answer 1

• Lung disease associated with Aspergillus fungal infection

NOTE: Aspergillus infection is usually caused by Aspergillus fumigatus

Question 2

Aetiology

Answer 2

Inhalation of Aspergillus spores can produce THREE different clinical pictures:

• Aspergilloma
o Growth of an A. fumigates mycetoma ball in a pre-existing lung cavity (e.g. postTB, old infarct or abscess)

• Allergic Bronchopulmonary Aspergillosis (ABPA)
o Colonisation of the airways by Aspergillus leads to IgE and IgG-mediated immune
responses
o Usually occurs in asthmatics
o The release of proteolytic enzymes, mycotoxins and antibodies leads to airway
damage and central bronchiectasis

• Invasive Aspergillosis
o Invasion of Aspergillus into lung tissue and fungal dissemination
o This occurs in immunosuppressed patients (e.g. neutropenia, steroids, AIDS)

Question 3

Epidemiology

Answer 3

• UNCOMMON

* Mainly occurs in the ELDERLY and IMMUNOCOMPROMISED

Question 4

Presenting symptoms

Answer 4

• Aspergilloma
o ASYMPTOMATIC
o Haemoptysis (potentially massive)

• ABPA
o Difficult to control asthma
o Recurrent episodes of pneumonia with wheeze, cough, fever and malaise

• Invasive Aspergillosis
o Dyspnoea
o Rapid deterioration
o Septic picture

Question 5

Signs on physical examination

Answer 5

• Tracheal deviation (only with very large aspergillomas)
• Dullness in affected lung
• Reduced breath sounds
• Wheeze (in ABPA)
• Cyanosis (possible in invasive aspergillosis)

Question 6

Investigations (aspergilloma)

Answer 6

o CXR
• May show a round mass with a crescent of air around it
• Usually found in the upper lobes

o CT or MRI - may be used if CXR is unclear

o NOTE: sputum cultures may be negative if there is no communication between the cavity colonised by Aspergillus and the bronchial tree

Question 7

Investigations (ABPA)

Answer 7

o Immediate skin test reactivity to Aspergillus antigens
o Eosinophilia
o Raised total serum IgE
o Raised specific serum IgE and IgG to A. fumigatus

o CXR
• Transient patchy shadows
• Collapse
• Distended mucous-filled bronchi
• Signs of complications:
▪ Fibrosis in upper lobes
▪ Bronchiectasis

o CT
• Lung infiltrates
• Central bronchiectasis

o Lung Function Tests
• Reversible airflow limitation
• Reduced lung volumes/gas transfer

Question 8

Investigations (invasive aspergillosis)

Answer 8

o Aspergillus is detected in cultures or by histological examination

o Bronchoalveolar lavage fluid or sputum may be used diagnostically

o Chest CT
• Nodules surrounded by a ground-glass appearance (halo sign)
• This is caused by haemorrhage into the tissue surrounding the fungal invasion