Allergic bronchopulmonary aspergillosis with marked peripheral blood eosinophilia and pulmonary eosinophilia: A case report

BACKGROUND: Allergic bronchopulmonary aspergillosis (ABPA) is an immune-related pulmonary disease caused by sensitization of airway by Aspergillus fumigatus. The disease manifests as bronchial asthma and recurring pulmonary shadows, which may be associated with bronchiectasis. The diagnosis of ABPA mainly depends on serological, immunological, and imaging findings. Pathological examination is not necessary but may be required in atypical cases to exclude pulmonary tuberculosis, tumor, and other diseases through lung biopsy. CASE SUMMARY: An 18-year-old man presented with recurrent wheezing, cough, and peripheral blood eosinophilia. Chest computed tomography showed pulmonary infiltration. There was a significant increase in eosinophils in bronchoalveolar lavage fluid. There was no history of residing in a parasite-endemic area or any evidence of parasitic infection. Pathologic examination of bronchoalveolar lavage fluid excluded fungal and mycobacterial infections. The patient was receiving medication for comorbid diseases, but there was no temporal correlation between medication use and clinical manifestations, which excluded drug-induced etiology. Histopathological examination of lung biopsy specimen showed no signs of eosinophilic granulomatosis with polyangiitis, IgG4-related diseases, or tumors. The diagnosis of ABPA was considered based on the history of asthma and the significant increase in serum Aspergillus fumigatus-specific immunoglobulin (Ig)E. Eosinophil-related diseases were excluded through pathological biopsy, which showed typical pathological manifestations of ABPA. CONCLUSION: The possibility of ABPA should be considered in patients with poorly controlled asthma, especially those with eosinophilia, lung infiltration shadows, or bronchiectasis. Screening for serum IgE, Aspergillus fumigatus-specific IgE and IgG, and alveolar lavage can help avoid misdiagnosis.