Case 90

1. Presented by: Eitan Halper-Stromberg MD and reviewed by Sean Zhang MD PhD

An adult immunosuppressed patient presents with a chief complaint of a red, nodular, rash on their arms, legs, and trunk. They first noticed the rash on the arms two days ago. It has since spread to their trunk and legs. The rash is not painful or itchy. They have no other symptoms. They are currently on posaconazole and mereponem from a previous infection, presumed unrelated.

Vitals on admission are: T 37.4 BP 113/64 HR 79 RR 16

Physical exam is notable for bilateral subcutaneous, dry, erythematous nodules on arms, legs, and trunk. Investigation of the rash is undertaken with two biopsies of a cutaneous and mucosal lesion, that both demonstrate angioinvasive fungal infection. The posaconazole is apparently not helping.

A fungus was recovered from one of their peripheral blood culture samples on the day the patient presented, showing white colonies, and on microscopy demonstrate banana shaped macroconidia and ovoid microconidia. The organism identified is a soil dweller and frequently caused fungal keratitis. It can sometimes cross-react with Aspergillus serum galactomannan assay.

Which organism is the most likely etiology of the infection?