Atypical haemolytic uremic syndrome with posterior reversible encephalopathy syndrome in an adolescent: a rare case report

Atypical hemolytic uremic syndrome (aHUS) is a group of disorders that affect kidneys which is rare type of HUS that differs from classical hemolytic uremic syndrome (HUS) by absence of prodromal phase consisting of episodes of diarrhoea due to preceding shiga toxin E. coli (STEC-HUS) infection and is 5% of all HUS cases. Approximately 50% cases present with clinical triad of hemolytic anemia, thrombocytopenia and renal insufficiency. However, it can have unusual clinical features in form of central nervous system involvement. This case, of a 15-year-old Indian boy, is one such rare presentation of atypical haemolytic uremic syndrome associated with posterior reversible encephalopathy syndrome (PRES), or reversible posterior leukoencephalopathy syndrome (RPLS) who presented with anaemia, anasarca, papilledema, hypertension, episodic seizures and significant magnetic resonance imaging (MRI) brain findings. We report this uncommon combination of two syndromes to provide useful insight for clinicians to approach and diagnose such presentation in paediatric patients.