What are some contraindications of local infiltration?

• A. Infection or acute inflammation
• B. No contraindications
• C. Chronic systemic disease only
• D. Patient intolerance to loud noises

Answer: (A)

The key idea is recognizing when local infiltration anesthesia should be avoided. An infection or acute inflammation at the injection site is a contraindication because inflamed tissue becomes acidic, which shifts the local anesthetic to its ionized form. The ionized form doesn’t readily cross nerve membranes, making the anesthetic far less effective and unpredictable. Injecting into infected tissue also risks spreading bacteria and complicating healing, so an alternative plan is preferred—such as using a different technique, delaying the procedure, or treating the infection first if possible.

That’s why this option is the best choice. Statements claiming there are no contraindications, or that only chronic systemic disease or non-relevant factors like intolerance to loud noises matter, aren’t correct in this context; these do not properly reflect the practical contraindication posed by active infection or acute inflammation at the injection site.