Allergic bronchopulmonary aspergillosis: a review of a disease with a worldwide distribution.

Allergic bronchopulmonary aspergillosis (ABPA), an immunologically mediated lung disease, occurs predominantly in patients with asthma. This chronic relapsing disorder ranges clinically from mild asthma to fatal destructive lung disease and is caused by hypersensitivity to colonized Aspergillus fumigatus (Af). The immunopathogenesis of the disease is yet to be understood clearly. Specific IgE-Af and IgG-Af, the serological markers, contribute to the diagnosis. Radiologically, ABPA is characterized by fleeting pulmonary infiltrates often confused with pulmonary tuberculosis. However, central bronchiectasis on computed tomography is considered to be the hallmark of the disease. Early diagnosis and therapy with prednisolone, the cornerstone of management, could alter the course of the disease and prevent the development of end-stage lung fibrosis.