Amoxicillin Allergy in Children: Five-Day Drug Provocation Test in the Diagnosis of Nonimmediate Reactions

QUESTION 1: What is the risk of a repeat reaction to amoxicillin or a cephalosporin in children with a history of a non-immediate reaction to amoxicillin?

“…Both studies found SPT to be poorly predictive of OCT. In a prospective cohort study of 141 children with a history of an NIR to amoxicillin, none had a positive SPT despite three (2.1%) children having a positive IDT and 14 (9.9%) having a positive amoxicillin OCT 7. Similarly, in another study of 337 children who experienced an NIR to amoxicillin, only three (0.9%) had a positive SPT despite 25 (7.4%) having a positive amoxicillin OCT 8…”

“…NIRs to oral amoxicillin have been reported in 6.8%–12.4% of the paediatric population 7 9 16–18. Most commonly these are mild, self-limiting cutaneous reactions and occur in the setting of a concurrent viral illness.…”

“…The concentration of amoxicillin administered intradermally was 20 mg/mL7 8 or 25 mg/mL9 with all studies considering a weal of more than 3 mm as a positive result (provided the control was negative). In two studies, children whose IDT was negative or who tested positive but had a history of a mild cutaneous reaction proceeded to amoxicillin OCT 7 8. One challenged all children, regardless of their IDT result 9.…”

“…Two studies performed amoxicillin SPT prior to amoxicillin OCT 7 8. Both studies found SPT to be poorly predictive of OCT.…”

“…Two studies used a three-dose graded challenge starting at 1/10th of a dose and titrating up to a full therapeutic dose for 5 days 7 8. Two studies gave the therapeutic weight-based dose for a maximum of only 48 hours 9 10.…”