Remove a Penicillin Allergy Label: Safe, and Saves Money

William T. Basco, Jr., MD, MS


December 31, 2019

Emergency department (ED) clinicians frequently are told that a child presenting to them for care has a penicillin allergy. A 2017 study[1] (reviewed here) evaluated children whose parents reported upon admission to the ED that the child had a penicillin allergy and found that 76% of these children were at low risk for a true penicillin allergy. A subset of the children were tested for penicillin allergy, and all were able to tolerate a three-step testing sequence consisting of a skin prick test, followed by subcutaneous injection, and ultimately an oral penicillin challenge. Their families were told that their children were not allergic to penicillin.

The same investigators have now conducted a follow-up study[2] that reassessed the children in the earlier study. Their aim was to determine whether the children who had been found to not be penicillin allergic had had the penicillin allergy label removed from their medical records. They also evaluated antibiotics prescribed to those children as they aged.

Each child's parents or caregiver and the child's primary care provider were contacted to determine whether penicillin allergy was still listed in the child's medical record, and whether the child had been treated with penicillin or a drug that contained amoxicillin after the initial ED visit.

Of the original 100 children tested for penicillin allergy after the ED visit, 81% of the parents completed the follow-up telephone survey. Most (90%) of those parents were aware of their child's penicillin allergy testing results, and 80% said they had notified the child's primary care provider of the test results. The investigators were able to contact 98% of the primary care providers, but 84% reported that they had not been notified by families that the child had undergone penicillin allergy testing or of the results of the testing.

Slightly more than half of the children's medical records still contained a penicillin allergy label. A total of 46 prescriptions for antibiotics (about half of which were for amoxicillin or penicillin) had been given to 36 of the children. Among those children who received amoxicillin, penicillin, or amoxicillin-clavulanate, only one developed a symptom (a rash) after taking the medication, and that child was relabeled as penicillin allergic.

This represented a cost savings of approximately $1300 per child, because subsequent infections could be treated with amoxicillin or penicillin, which are generally cheaper drugs. The researchers concluded that among children at low risk for true penicillin allergy and who tolerated penicillin allergy testing, most were able to take penicillin or amoxicillin without developing a reaction. The removal of the penicillin allergy label stands to save the health system substantial money.


I really liked the original study, and it became one of the most read Medscape Pediatrics Viewpoints of 2017. So, it's nice to see this follow-up study that helps validate the conclusions of the initial study—that children who meet low-risk criteria could successfully complete penicillin allergy testing. This study shows that those same children can take courses of amoxicillin or penicillin later and not experience allergic reactions. In the previous study, the investigators had suggested that the questionnaire used to obtain details on the child's purported allergic reaction and family history of atopic illness was not quite ready for prime time, so stay tuned for more information. My conclusions from that previous viewpoint still hold. We should be much more careful about documenting symptoms and physical findings when patients or parents report reactions to medications and careful not to label a patient as penicillin-allergic without good evidence based on history and physical examination by a medical provider.


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