Which antibiotic would be best for a child with a penicillin allergy requiring premedication prior to dental appointments?

• A. Cephalosporin
• B. Amoxicillin
• C. Ampicillin
• D. Azithromycin

Answer: (D)

The situation tests choosing a safe and effective antibiotic for dental prophylaxis in a child with a penicillin allergy. In this context, a macrolide such as azithromycin is preferred because it provides good coverage against the typical oral streptococci encountered during dental procedures, it is well tolerated in children, and it can be given as a convenient single-dose premedication. Importantly, it avoids penicillin exposure and minimizes concerns about cross-reactivity seen with penicillins and, to a lesser extent, with cephalosporins in true penicillin-allergic patients.

Penicillins like amoxicillin or ampicillin are not suitable due to the allergy. A cephalosporin might be considered in some cases, but there is residual concern about cross-reactivity in penicillin-allergic individuals, making it less ideal for premedication when penicillin allergy is present. Clindamycin is another alternative, but it carries a higher risk of gastrointestinal side effects and C. difficile infection, so azithromycin’s tolerability and dosing convenience often make it the better choice for a child requiring dental prophylaxis.