Reye Syndrome (Reye's Syndrome) By Christopher P Raab, MD, Sidney Kimmel Medical College at Thomas Jefferson University Reviewed / Revised Feb 2023 View Patient Education Symptoms and Signs Diagnosis Treatment Prognosis Key Points Topic Resources Overview of Reye Syndrome Reye syndrome is a rare form of acute encephalopathy and fatty infiltration of the liver that occurs almost exclusively in children < 18 years old.