Iodinated contrast media allergy is rare in patients undergoing sialography

BACKGROUND: Iodinated contrast media allergy is considered as a strong contra-indication for performing sialography. There is little evidence to support this approach. OBJECTIVE: To evaluate the rate of iodinated contrast media (ICM) allergy in subjects undergoing sialography and to assess the risk for allergic responses in patients with a previous diagnosis of allergy. METHODS: We retrospectively reviewed sialo-CBCT studies performed from 2014 to 2019. During the study period we implemented a protocol for performing sialo-CBCT in patients with a prior diagnosis of allergy: 1) Clinical data were collected from a questionnaire and medical records. 2) No premedication was administered but, instead, oxygen, epinephrine and a resuscitation cart were accessible. 3) Following the procedure, each patient was observed for one hour and contacted by telephone 24 hrs later. RESULTS: No allergic responses were documented in the medical records of 1515 subjects following sialo-CBCT studies, including 13 individuals previously diagnosed with ICM allergy. Investigation of the subgroup with prior allergy disclosed that the range of injected volume was between 2 ml to 6.2 ml per patient and that complete secretion of ICM was detected in 7 of 13 patients. In the remainder of subjects, retention rates of 5-50% were observed. CONCLUSIONS: Allergic reactions are exceedingly rare following sialo-CBCT studies regardless of a previous diagnosis of allergy. Pre-medication with corticosteroids and antihistamines is usually not warranted.