Case Report: Diagnosis of bronchopulmonary candidiasis—refractory airway hyperresponsiveness, severe pneumonia, and normal serological markers

Background Bronchopulmonary candidiasis is a clinically common type of pulmonary fungal disease, primarily caused by infection with Candida species (mostly Candida albicans ). It typically manifests as a secondary infection when the body’s resistance is compromised. Clinically, bronchopulmonary candidiasis is primarily classified into three types: (1) bronchitic, (2) pneumonic, and (3) hypersensitivity. Methods This paper reports two cases of bronchopulmonary candidiasis. The first case presented with bronchitis-type manifestations. Imaging studies showed no evidence of severe pneumonia, but the patient had persistent airway hyperresponsiveness that led to difficulty in weaning from mechanical ventilation. Candida albicans was identified in the bronchoalveolar lavage fluid (BALF), supporting a diagnosis of Candida bronchitis. The patient was successfully weaned following targeted antifungal therapy. The second case presented with the pneumonia variant, clinically manifesting as severe pneumonia. Candida albicans was also isolated from the BLAF. The patient recovered and was discharged after receiving combination antifungal therapy with caspofungin and isavuconazole. Results Serological markers for fungal infection were normal in both patients, but pathogen cultures from BALF revealed Candida albicans growth. Combined with clinical presentations, these findings supported diagnoses of invasive Candida bronchitis and pneumonia, respectively. Conclusion This report indicates that the clinical manifestations of bronchopulmonary candidiasis may be atypical relative to radiological and serological indicators. Although a single positive BALF culture is insufficient for definitive diagnosis, its integration with clinical characteristics can provide a crucial diagnostic clue. These cases thus provide valuable reference points for clinical diagnosis, though definitive validation through histopathological examination remains necessary.