Aims

Antibiotic allergies are reported in 5–15% of children. This study aimed to evaluate the impact of common β‐lactam antibiotic allergy labels (AALs) on hospital treatment, focusing on length of stay and appropriateness of antibiotic prescribing.

Methods

This was a retrospective cohort study over 21 months at the Royal Children's Hospital Melbourne, Australia. A subset of children with the most common β‐lactam allergies, and who required admission for intravenous antibiotics over a 12‐month period, was analysed for appropriateness of prescribing. Non‐allergic patients were matched to evaluate associations between AALs and hospital treatment.

Results

There were 98 912 children admitted over the study period, of whom 938 (1%) had at least one AAL on first admission. Of all encounters, 5145 (2.5%) were for children with AALs. The most common AALs were to amoxicillin and amoxicillin‐clavulanic acid combinations (40.8%), cefalexin (14.4%) and trimethoprim‐sulfamethoxazole (9.7%). For the subset, there were 66 admissions for children who required intravenous antibiotics. Documentation was adequate for 27% of AALs. Inappropriate prescribing occurred in almost half (47%). Hospital stay was longer for children with AALs (median 4.7 days; IQR 2.3–9.2) compared to non‐allergic controls (median 3.9 days; IQR 1.9–6.8; P  = .02). Children with AALs were more likely to receive restricted antibiotics (aOR 3.03; 95% CI, 1.45–6.30; P  = .003).

Conclusion

This is the first study to demonstrate high rates of inappropriate prescribing in children with AALs. Children with AALs were significantly more likely to receive restricted antibiotics and had a longer length of stay compared with non‐allergic controls.