gadolinium contrast agents have been safely used in children and adults for over 20 years . the incidence of gadolinium allergy in children is between 0.04 and 0.1% , based on published case series [ 1 , 2 , 3 ] . in those patients with central nervous system tumors , gadolinium contrast injection is absolutely necessary to monitor disease status . we report a case of a 13-year - old girl , with a history of low - grade glioma , who developed shortness of breath and urticaria following injection of intravenous gadolinium while in the mri scanner . the incidental mri findings reported may assist in recognizing gadolinium allergy in younger patients who are under anesthesia during their neuroimaging studies . a 13-year - old girl , diagnosed with a posterior fossa juvenile pilocytic astrocytoma , status post gross total resection 1 year prior , underwent routine mri neuroimaging with and without gadolinium . following an injection of intravenous gadopentetate dimeglumine the patient was promptly removed from the mri scanner and given intravenous diphenhydramine , after which she quickly returned to baseline . brain mri initially reported stable post - operative changes and no evidence of residual neoplasm . however , on retrospective review in light of the history , several extracranial areas of abnormality were discovered , as shown in fig . 1 . the post - gadolinium mri revealed multiple areas of contrast - enhancing soft tissue lesions of the bilateral face consistent with the observed urticaria . additionally , there was an area of contrast enhancement of the right ear . the patient has had subsequent mri evaluations with gadolinium following pretreatment with corticosteroids and antihistamines without incident and with complete resolution of the aforementioned findings . our reported mri findings of post - gadolinium hypersensitivity are admittedly coincidental ; however , recognition of gadolinium allergy can be critical . severe anaphylactoid reactions and even death have been well described in the literature [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ] . reported a gadolinium allergy incidence of 0.4% in their pediatric population and a 7% overall incidence of severe reactions . patients can have allergic reactions to gadolinium compounds in spite of pretreatment with antihistamines and corticosteroids . those patients with a prior history of allergic reaction to iodinated compounds may be at risk for reactions to gadolinium . in the case of our patient , she had had several previous injections without incident and had no prior history of allergic reactions . our case illustrates extracranial manifestations of gadolinium allergy that may alert the neuroradiologist , particularly in cases where patients are under anesthesia and may have less subtle findings .
a 13-year - old girl with a remote history of juvenile pilocytic astrocytoma developed acute onset flushing , tachycardia and shortness of breath immediately following administration of gadopentetate dimeglumine during routine brain mri that subsided following intravenous diphenhydramine . a retrospective review of the mri results revealed multiple areas of contrast enhancement of the face , consistent with observed urticaria . 
 the patient received pretreatment medications prior to subsequent gadolinium injections without incident . 
 gadolinium allergy is extremely rare and has been reported in less than 0.1% of injections . 
 however , in patients who undergo anesthesia for mri studies , similar subtle extracranial mri findings should alert the neuroradiologist to possible gadolinium allergy that may warrant premedication prior to future injections .