Exophiala pneumonia identified in immunocompetent woman with lung disease

Background

Exophiala, a genus of saprotrophic black fungi commonly found in the environment, is typically associated with cutaneous infections in immunocompromised hosts and rarely manifests as pneumonia. Here, we report the first case of Exophiala pneumonia in Pakistan, occurring in an immunocompetent, middle-aged female with interstitial lung disease.

Case presentation

A 56-year-old female presented with a two-week history of malaise and a cough productive of black sputum. On auscultation, fine crackles were heard in the bilateral posterior middle and lower lung fields. Chest radiography showed features of usual interstitial pneumonia with patchy and dense reticular opacities in the middle and lower lung lobes bilaterally. Bronchoscopy was performed, and bronchoalveolar lavage was sent to the microbiology laboratory for culture. Gram stain findings revealed numerous pus cells, primarily neutrophils, along with septate hyphae, which were also confirmed on potassium hydroxide smear. The results were communicated to the treating physician, and the patient was started on intravenous voriconazole. After four days of incubation at 25°C and 37°C, colonies of mold were observed on the culture, which were identified as Exophiala jeanselmei on Lactophenol Cotton Blue staining. After one week of treatment, the patient showed clinical improvement and was discharged on oral voriconazole with outpatient follow-up.

Conclusions

Bronchoalveolar lavage with an elevated neutrophil count and abnormal pulmonary imaging should be considered characteristic of both bacterial and fungal pneumonia. Cultures must be sent not only for bacterial workup but also for fungal culture, as it employs special techniques and prolonged incubation for the isolation of fungi. Good microbiological acumen and enhanced communication between the lab and clinical teams facilitate appropriate diagnosis and early initiation of therapy.