A case of severe anaphylactic reaction after administration of diagnostic-dose ferumoxytol in a pediatric patient

We describe a case of anaphylaxis during administration of intravenous (IV) ferumoxytol as a magnetic resonance imaging (MRI) contrast agent in a 4-year-old patient with complicated past medical history including YARS genetic mutation with resultant liver failure and deceased donor liver transplantation, stage IV chronic kidney disease (CKD), and hypertension. The patient was noted to have labored breathing 4 min after initiation of ferumoxytol infusion and was subsequently rapidly intubated and returned to the intensive care unit (ICU) for monitoring. Anaphylactic reactions to therapeutic doses of ferumoxytol led to issuance of a black box warning by the FDA in 2015. Adverse reactions to lower-dose ferumoxytol used in diagnostic imaging, however, are rare and there has been a paucity of documented anaphylactic reactions in the literature.