Pulmonary aspergillosis.

Aspergillus species are ubiquitous in the environment and are inevitably inhaled into the airways. Inhalation of Aspergillus conidia or mycelium fragments may result in colonisation of the airways. In susceptible hosts colonisation may subsequently cause disease. Patients with pre-existent cavities may develop aspergillomas which may be quiescent or cause symptoms especially recurrent haemoptysis. Acute invasive disease is potentially lethal in patients who are vulnerable to infection due to underlying lung diseases or immunosuppression. In addition to its ability to colonise the human respiratory tract, Aspergillus has a significant potential to act as a powerful allergen resulting in Aspergillus asthma and allergic bronchopulmonary aspergillosis. The various presentations of pulmonary disease caused by Aspergillus are reviewed here, focusing primarily on clinical aspects rather than basic science.