A patient reports a documented anaphylactic reaction to procaine many years ago. She now needs infiltration anaesthesia for a skin lesion. Which statement is correct?
- A An amide such as lidocaine may be used safely after careful assessment ✓
- B All local anaesthetics are contraindicated and general anaesthesia is mandatory
- C Only another ester such as chloroprocaine can be used
- D Cross-reactivity occurs with all agents sharing an aromatic ring
Correct answer: A. An amide such as lidocaine may be used safely after careful assessment
Explanation
True IgE-mediated allergy to local anaesthetics is rare and almost confined to the ester group. Esters are metabolised to para-aminobenzoic acid (PABA), which accounts for their allergenicity, so cross-reactivity occurs between esters. Amides such as lidocaine have no PABA metabolite and show no immunological cross-reactivity with esters. Preservatives such as methylparaben, itself a PABA derivative, should also be avoided in genuinely allergic patients.
Reference: Morgan and Mikhail's Clinical Anesthesiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.