Posterior reversible encephalopathy syndrome with PLEDs-plus due to mesalamine

A 32-year-old lady developed status epilepticus and acute visual loss while on mesalamine for Crohn's disease. Her clinical course and magnetic resonance imaging (MRI) were suggestive of posterior reversible encephalopathy syndrome (PRES). She had periodic lateralized epileptiform discharges plus (PLEDs-plus) on electroencephalogram (EEG), which responded to sodium valproate. Her vision improved from counting fingers at one-meter distance to 6/12. Though different cytotoxic drugs have been implicated as causative agents, this is the first case report of mesalamine-induced PRES. This case highlights the need for aggressive treatment of PLEDs-plus with EEG monitoring using a broad-spectrum antiepileptic drug like valproate, which has contributed to the rapid reversibility of vision in PRES subjects, and the need for a thorough drug history for etiological clues.