Aspergillus Lung Disease Flashcards
Define Aspergillus Lung Disease?
Lung disease associated with Aspergillus fungal infection
What is Aspergillus Infection caused by?
Aspergillus fumigatus
What are the three different clinical pictures caused by inhalation of aspergillus spores?
Aspergilloma
Allergic Bronchopulmonary Aspergillosis (ABPA)
Invasive Aspergillosis
What is the aetiology of Aspergilloma?
Growth of an A.fumigates mycetoma ball in a pre-existing lung cavity (e.g. post-TB, old infarct or abscess)
What is the aetiology of Allergic Bronchopulmonary Aspergillosis (ABPA)?
Colonisation of the airways by Aspergillus leads to IgE and IgG-mediated immune responses
Usually occurs in asthmatics
The release of proteolytic enzymes, mycotoxins and antibodies leads to airway damage and central brochiectasis
What is the aetiology of Invasive Aspergillosis?
Invasion of Aspergillus into lung tissue and fungal dissemination
This occurs in immunosuppressed patients (e.g. neutropenia, steroids, AIDS)
What is the epidemiology of Aspergillus Lung Disease?
UNCOMMON
Mainly occurs in the ELDERLY and IMMUNOCOMPROMISED
What are the presenting symptoms of Aspergilloma?
ASYMPTOMATIC
Haemoptysis (potentially massive)
What are the presenting symptoms of ABPA?
Difficult to control asthma
Recurrent episodes of pneumonia with wheeze, cough, fever and malaise
What are the presenting symptoms of Invasive Aspergillosis?
Dyspnoea
Rapid deterioration
Septic picture
What are the signs of Aspergillus Lung Disease?
Tracheal deviation (only with very large aspergillomas)
Dullness in affected lung
Reduced breath sounds
Wheeze (in ABPA)
Cyanosis (potentially in invasive aspergillosis)
What investigations would you do for Aspergilloma?
CXR
CT or MRI
Sputum Cultures
Why do we do a CXR for Aspergilloma?
May show a round mass with a crescent of air around it
Usually found in the upper lobes
Why do we do CT or MRI for Aspergilloma?
May be used if CXR is unclear
Why might Sputum Cultures be negative for Aspergilloma?
If there is no communication between the cavity colonised by Aspergillus and the bronchial tree
What investigations do you do for ABPA?
Immediate skin test reactivity to Aspergillus antigens
Eosinophilia
Raised total serum IgE
Raised specific serum IgE and IgG to A.fumigatus
CXR
CT
Lung Function Tests
What do we see on a CXR for ABPA?
Transient patchy shadows
Collapse
Distended mucous-filled bronchi
Signs of complications (Fibrosis in upper lobes, bronchiectasis)
What do we see on a CT for ABPA?
Lung infiltrates
Central bronchiectasis
What do we see on Lung function tests for ABPA?
Reversible airflow limitation
Reduced lung volumes/gas transfer
What investigations do you do for Invasive Aspergillosis?
Aspergillus is detected in cultures or by histological examination
Bronchoalveolar lavage fluid or sputum may be sued diagnostically
Chest CT
What do we see on a Chest CT for Invasive Aspergillosis?
Nodules surrounded by a ground-glass apperance (halo sign)
This is caused by haemorrhage into the tissue surrounding the fungal invasion
