Aspergillosis Overlap Syndromes

Aspergillus species can cause a variety of pulmonary clinical syndromes depending on the immune status of the patient, the presence of the underlying lung disease, and the lung function. These syndromes include chronic pulmonary aspergillosis, allergic bronchopulmonary aspergillosis (ABPA), and invasive aspergillosis. Each of these syndromes has unique clinical, radiological, and serological manifestations but they may also overlap and progress from one entity to another. There is scarcity of the literature on these overlap syndromes. However, there are some reports of patients having ABPA and allergic aspergillus sinusitis and ABPA with fungal balls that progressed to invasive aspergillosis. Aspergillus species are also implicated in the pathogenesis of other respiratory conditions. The most important entities are hypersensitivity pneumonitis, mucoid impaction in bronchi, and bronchocentric granulomatosis. These clinical conditions tend to have similar features to the classic aspergillus-related syndromes. These diseases develop independently but similar clinical features raise the possibility that they may represent the spectrum of the same disease. It is imperative to know about these overlap syndromes to avoid unnecessary investigations as it may have an impact on the management of these patients. In this chapter we will be discussing different aspergillus-related overlap syndromes, specifically highlighting the clinical manifestations, treatment options, and outcomes.