Severe Acute Hepatitis of Unknown Etiology Presenting as Pediatric Acute Liver Failure: Analysis of Likely Etiology, Clinical Course and Outcome.

Adenovirus, adeno-associated virus, and severe acute respiratory syndrome-coronavirus-2 (SARS-COV2) have been recently implicated as probable causative agents of severe acute hepatitis of unknown etiology reported from most of Europe. High mortality and liver transplantation (LT) rates have been observed in those presenting with acute liver failure (ALF). Such cases have not been reported from the Indian subcontinent. We analyzed the etiologies, clinical course, and in-hospital outcomes of cases of severe acute hepatitis with ALF presenting to us between May and October 2022. A total of 178 children presented with severe acute hepatitis of known/unknown etiology including 28 presenting as ALF. Eight of them fulfilled the definition of severe acute hepatitis of unknown etiology presenting as ALF. Adenovirus was not associated with cases of ALF in these children. SARS-COV2 antibodies were detected in 6 (75%) of them. Children with severe acute hepatitis of unknown etiology presenting as ALF were young (median age 4 years), had hyper-acute presentation with a predominance of gastrointestinal symptoms, and a fulminant course with worse outcomes (native liver survival 25%). Expedited evaluation of these children for LT would be the key to management.