Penicillin ↔ Cephalosporin Cross-Reactivity (Side-Chain Based)
Pick the reported allergen and the drug you want to use. This reproduces Figure 2: identical R1 side chains are marked “Same” (red); all others “Different” (green).
Clinical context matters. This tool reflects side-chain relationships only from the practice-parameter Figure 2; it does not model IgE/timing/phenotype, skin-testing, or de-labeling protocols.
This tool is for educational use only and is not medical advice. All use subject to Terms and Conditions.
This code was generated with a LLM, October 2025. I have personally cross-checked every drug combination in this table and confirm this information is correct according to the source article below.
~Clay Smith, MD
Figure 2: From cited article below
Source
Drug Allergy Practice Parameter Updates to Incorporate Into Your Clinical Practice. J Allergy Clin Immunol Pract. 2023 Feb;11(2):356-368.e5. doi: 10.1016/j.jaip.2022.12.002. Epub 2022 Dec 20. PMID: 36563781.
This broader table includes more beta-lactam agents and was developed for QI at a single institution using literature review and expert opinion.
Supplemental Figure 1 from cited article
Source
Impact of an Antibiotic Side-Chain-Based Cross-reactivity Chart Combined With Enhanced Allergy Assessment Processes for Surgical Prophylaxis Antimicrobials in Patients With β-Lactam Allergies. Clin Infect Dis. 2021;72(8):1404-1412. doi:10.1093/cid/ciaa232.