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.