Presentation
The patient, a known case of diabetes mellitus, presented to the department of emergency medicine with fever, productive cough, and dyspnea for one week. rt-PCR was performed for COVID-19, which was positive. He was started on supplemental oxygen due to low oxygen saturation (88% at room air).
Patient Data
HRCT chest (axial, coronal, and sagittal views) shows bilateral patchy ground-glass opacities, septal thickening, and subpleural band opacities. In the superior segment of left lower lobe, two cavitary lesions with adjacent consolidation are seen. Irregular & intersecting strands are noted within the cavitary lesions which–along with the pericavitary consolidations–give an appearance of a "bird's nest".
The radiological picture is suggestive of atypical fungal infection.
The patient was started on liposomal amphotericin B, and taken for surgery (segmental resection of the lung) on the 15th day when he became rt-PCR negative for COVID-19. The histopathological examination of the lung tissue revealed the presence of mucormycosis.
Case Discussion
Opportunist fungal infections are increasing in frequency in patients afflicted with COVID-19 pneumonia.
Both pulmonary aspergillus and mucormycosis are similar in clinical presentation and both are more common in the diabetics, chronically immunosuppressed, and those undergoing cancer chemotherapy. Widespread use of glucocorticoids to prevent cytokine storms may account for the increasing incidence of these infections in COVID-19 patients. Certain laboratory tests (such as galactomannan in bronchoalveolar lavage) can be useful for the diagnosis of invasive pulmonary aspergillosis. However, no such markers exist for pulmonary mucormycosis.
In the correct clinical setting, specific appearances on computed tomographic images such as the bird’s nest sign and halo sign are suggestive of invasive pulmonary fungal infections.