Tramline shadowing, finger-in-glove opacities and toothpaste shadows are also prevalent findings.When utilising high-resolution CT scans, there can be a better assessment of the distribution and pattern of bronchiectasis within the lungs, and hence this is the tool of choice in the radiological diagnosis of ABPA. Central (confined to medial two-thirds of the medial half of the lung) bronchiectasis that peripherally tapers bronchi is considered a requirement for ABPA pathophysiology, though in up to 43% of cases there is a considerable extension to the periphery of the lung.Mucoid impaction of the upper and lower airways is a common finding. Plugs are hypodense but appear on CT with high attenuation (over 70 Hounsfield units) in up to 20% of patients. Where present it is a strong diagnostic factor of ABPA and distinguishes symptoms from other causes of bronchiectasis.CT scans may more rarely reveal mosaic-appearance attenuation, centrilobular lung nodules, tree-in-bud opacities and pleuropulmonary fibrosis (a finding consistent with CPA, a disease with ABPA as a known precursor). Rarely other manifestations can be seen on CT scans, including military nodular opacities, perihilar opacities (that mimic hilar lymphadenopathy), pleural effusions and pulmonary masses. Cavitation and aspergilloma are rarer findings, not exceeding 20% of patients, and likely represent a shift from ABPA to CPA if accompanied by pleural thickening or fibrocavitary disease. Culture
Culturing fungi from sputum is a supportive test in the diagnosis of ABPA, but is not 100% specific for ABPA as A. fumigatus is ubiquitous and commonly isolated from lung expectorant in other diseases.
There are challenges involved in long-term therapy with corticosteroids—which can induce severe immune dysfunction when used chronically, as well as metabolic disorders—and approaches have been developed to manage ABPA alongside potential adverse effects from corticosteroids.The most commonly described technique, known as sparing, involves using an antifungal agent to clear spores from airways adjacent to corticosteroid therapy. The antifungal aspect aims to reduce fungal causes of bronchial inflammation, whilst also minimising the dose of corticosteroid required to reduce the immune systems input to disease progression. The strongest evidence (double-blinded, randomized, placebo-controlled trials) is for itraconazole twice daily for four months, which resulted in significant clinical improvement compared to placebo, and was mirrored in CF patients. Using itraconazole appears to outweigh the risk from long-term and high-dose prednisone. Newer triazole drugs—such as posaconazole or voriconazole—have not yet been studied in-depth through clinical trials in this context.Whilst the benefits of using corticosteroids in the short term are notable, and improve quality of life scores, there are cases of ABPA converting to invasive aspergillosis whilst undergoing corticosteroid treatment. Furthermore, in concurrent use with itraconazole, there is potential for drug interaction and the induction of Cushing syndrome in rare instances. Metabolic disorders, such as diabetes mellitus and osteoporosis, can also be induced.In order to mitigate these risks, corticosteroid doses are decreased biweekly assuming no further progression of disease after each reduction. When no exacerbations from the disease are seen within three months after discontinuing corticosteroids, the patient is considered to be in complete remission.