Allergic bronchopulmonary aspergillosis (ABPA) occurs in patients with either asthma or cystic fibrosis, with growth of aspergillus hyphae in bronchial mucous. This can result in mucostasis with mucoid plugs, chronic inflammation with bronchial wall injury and bronchiectasis, and/or scarring of distal bronchioles (bronchiolitis obliterans). Symptoms may be minimal to severe, and may be superimposed on those of the underlying lung disease.