If the patient has a PABA allergy, which topical anesthetic should you use?

If the patient has a PABA allergy, which topical anesthetic should you use?

• A. Procaine
• B. Benzocaine
• C. Lidocaine
• D. Tetracaine

Answer: (C)

When a patient has a PABA allergy, you want to avoid ester-type local anesthetics because many of them metabolize to PABA, which can trigger an allergic reaction. Topical benzocaine, procaine, and tetracaine are all esters and thus carry a higher risk of PABA-related allergy. Lidocaine is an amide-type local anesthetic, and amides do not release PABA as a metabolite, so it presents a much lower risk of provoking a PABA allergy. Using lidocaine provides effective numbing without exposing the patient to PABA, making it the safer choice in this scenario.

When a patient has a PABA allergy, you want to avoid ester-type local anesthetics because many of them metabolize to PABA, which can trigger an allergic reaction. Topical benzocaine, procaine, and tetracaine are all esters and thus carry a higher risk of PABA-related allergy. Lidocaine is an amide-type local anesthetic, and amides do not release PABA as a metabolite, so it presents a much lower risk of provoking a PABA allergy. Using lidocaine provides effective numbing without exposing the patient to PABA, making it the safer choice in this scenario.