Aspergillosis

- caused by A.fumigatus (most common), A.flavus and A.niger
- these fungi are ubiquitous in environment and commonly found on decaying leaves and trees
- human infected by inhalation of spores
- 3 major forms

i) Allergic bronchopulmonary aspergillosis (ABPA)
- commoner among asthmatics with variable airflow obstruction
- Aspergillus grows in the wall of bronchi
- presents with wheeze, cough, fever and malaise, eventually produce proximal bronchiectasis
- type III hypersensitivity reaction
- suspect if asthma is refractory and is associated with fever, cough and grey/black sputum
- eosinophilia and IgE levels extremely high
- serum precipitins and skin prick test both positive
- abnormal chest X ray (transient pulmonary shadow)
- treatment: prednisolone 30mg daily and prolonged course of itraconazole (up to 4 months)

ii) Aspergilloma
- masses of fungal mycelia that grow in pre-existing lung cavities
- hemoptysis is common symptom
- CXR: round lesion with air halo above it
- high serum precipitins (continuing antigenic stimulation), negative skin prick test
- treatment: surgical resection, itraconazole (if unfit for resection), arterial embolisation if life threatening hemoptysis

iii) Invasive aspergillosis
- occurs in immunosuppressed
- presents with acute pneumonia, meningitis or intracerebral abscess, lytic bone lesions, granulomatous lesions in liver
- treatment: IV voriconazole or amphotericin B