For internal hordeolum caused by Staphylococcus aureus, which antibiotic regimen is most appropriate?

• A. Amoxicillin alone
• B. Dicloxacillin
• C. Erythromycin
• D. Augmentin

Answer: (D)

Staphylococcus aureus eyelid infections often involve beta-lactamase production, which can inactivate plain penicillins. An antibiotic that combines a penicillin with a beta-lactamase inhibitor, like amoxicillin–clavulanate, overcomes this resistance and provides reliable coverage against beta-lactamase–producing strains. That broader, more robust activity makes it the most appropriate systemic option for an internal hordeolum in this context. Erythromycin tends to have high resistance, and while a penicillinase-resistant penicillin can treat MSSA, it doesn’t address beta-lactamase producers as effectively as a combination product. Amoxicillin alone would be ineffective due to beta-lactamase.