Asthma and Fungus: Role in Allergic Bronchopulmonary Aspergillosis (ABPA) and Other Conditions

Asthma is an allergic, respiratory disorder characterized by hyper responsiveness of the airway to external stimuli. Considerable research is currently being directed towards understanding the role of environmental and genetic factors contributing to the development of asthma and its severity. Recent years have seen a substantial rise in evidence linking fungi to asthma. Few major clinical conditions associated with fungal sensitization and hypersensitive immune response are Allergic bronchopulmonary aspergillosis (ABPA), Allergic fungal rhinosinusitis (AFRS) and Severe asthma with fungal sensitization (SAFS). The most common fungi implicated in these conditions belong to genus Aspergillus, although an association with several other fungi has been described. In this review authors discuss the varying clinical characteristics of fungus induced respiratory complications in individuals with asthma. They also highlight the epidemiology of these conditions including their prevalence in children and their fungal etiological profile. Laboratory diagnostic methods and clinical case definitions have also been discussed. Future studies evaluating the role of fungal exposure and susceptibility to asthma are required. Till date there are no guidelines for the diagnosis and treatment of ABPA in pediatric population, thus it is also imperative to establish validated clinical definitions of fungal allergic manifestations in pediatric patients with asthma to fully understand this complex interaction.