Dental abscess with penicillin allergy — ORE Part 1 MCQ

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ModerateDental Pharmacology and TherapeuticsDental abscess with penicillin allergyORE Part 1

A 40-year-old woman has an acute apical abscess with fever and buccal cellulitis. Drainage of the source is arranged and an antibiotic adjunct is indicated. She has previously developed immediate urticaria and wheeze after penicillin. She is not pregnant and takes no regular medicines. Which antibiotic is most appropriate?

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Correct answer: A — Metronidazole

Explanation lettering: E = shown as A · A = shown as D · D = shown as E

E is correct. Fever and buccal cellulitis indicate systemic and spreading infection, so drainage should be accompanied by an antibiotic adjunct. In current UK dental prescribing practice, metronidazole is an appropriate alternative antibacterial for a dental abscess when penicillin cannot be used. Amoxicillin is contraindicated in a convincing immediate penicillin hypersensitivity reaction. Co-amoxiclav contains amoxicillin and is therefore also inappropriate; it is not a penicillin-free option. Clarithromycin is used in selected dental contexts but is not the standard first alternative for this acute odontogenic infection in the absence of a specific indication. Doxycycline is not the routine SDCEP first-choice alternative for acute dental abscess. Definitive local treatment and drainage remain essential; antibiotics do not replace source control.

Reference: Scottish Dental Clinical Effectiveness Programme (SDCEP). Management of Acute Dental Problems: Acute apical abscess, 2026. https://www.acutedentalproblems.sdcep.org.uk/guidance/management-of-oral-conditions/common-oral-conditions/acute-apical-abscess/