Children with confirmed nonimmediate allergic reactions to beta‐lactam antibiotics can develop tolerance after a long period of drug avoidance

Allergic reactions to beta-lactam antibiotics (βLs) can fade over time, the length of which depends on the effector mechanism and the culprit drug. Most studies investigating this subject included people with immediate reactions (IRs). There is little evidence on (T-cell dependent) non-immediate reactions (NIRs), particularly in children. We used drug provocation tests (DPT) to evaluate children with suspected allergies to βLs. Reactions were classified as IR or NIR. Previously evaluated children with confirmed NIRs to amoxicillin and amoxicillin/clavulanate were offered a 5-year follow-up DPT to assess loss of sensitivity. We compared children who tolerated the drug and those who were still allergic on rechallenge according to the age of appearance of reactions, sex, and atopic status. Of 665 children evaluated, 80 (12%) were confirmed as allergic: 54 NIRs (68%) and 26 IRs (32%). Regarding the type of rash, 59% had urticaria and 41% exanthem. Of the children with NIRs, 34 completed the study (62% female, 60% atopic). In the rechallenge, 50% showed tolerance. Among the children who had a reaction, 9 had urticaria and 8 exanthem. The children who showed tolerance were significantly younger than those who remained positive (p < .05). Among these children, 15 reported taking the same drug again, prescribed by their pediatrician, with good tolerance. T cell responses to βLs can subside. Children who experience NIRs to amoxicillin or amoxicillin/clavulanate can develop tolerance.