Brain phaeohyphomycosis secondary to immunosuppressant therapy due to Rhinocladiella mackenziei

ABSTRACT

Two cases of Rhinocladiella mackenziei have been noted in our institute, the first case in 2015 (post-renal transplant) and the second case in 2021 (post-COVID infection). Both the patients had received immunosuppressants for varying dura-tion. Both the cases presented to the hospital with neurological deficit secondary to brain abscess. On initial assessment, the melanized fungus was noted which was later identified as Rhinocladiella on culture and further confirmed with molecular meth-ods. Both the cases were treated with injection of L AmB, voriconazole and 5FC for a prolonged duration and later discharged when the condition improved. The renal transplant patient was advised lifelong voriconazole since he would continue to be on immunosuppressants. To our knowledge, the second patient diagnosed post-COVID could be the first case report of invasive dematiaceous fungal infection in an apparently immunocompetent individual. Both cases also highlight the challenges in man-agement such as designing an appropriate regimen, deciding the optimum duration of antifungal therapy, and managing the toxicities associated with long-term antifungal use. R. mackenziei is a frequently fatal melanized neurotropic fungus known to carry almost 100% mortality despite the combination of antifungal agents and surgery. Central nervous system infections due to R. mackenziei have been exclusively reported from the Middle East, except for cases recently reported from India.