Aphthous Ulceration Investigation — MFDS Part 1 MCQ

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ModerateOral MedicineAphthous Ulceration InvestigationMFDS Part 1

An otherwise well adult reports recurrent, painful oral ulcers that heal spontaneously between episodes. The history and examination are consistent with recurrent aphthous stomatitis, with no features suggesting a specific systemic disorder. Which blood-test panel is most appropriate as part of the initial investigation?

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Correct answer: A — Full blood count, serum ferritin, vitamin B12 and folate levels

Explanation lettering: D = shown as B · E = shown as C · B = shown as D · C = shown as E

A is correct. Recurrent aphthous stomatitis may be associated with anaemia or haematinic deficiency. Appropriate baseline investigation therefore includes a full blood count and measurement of ferritin, vitamin B12 and folate, allowing potentially treatable deficiencies or cytopenias to be identified. Further targeted investigations may include coeliac serology and inflammatory markers when ulcers are severe or persistent, or when the history suggests gastrointestinal or systemic inflammatory disease. Liver and thyroid function tests are not routine first-line investigations without relevant clinical features. HbA1c is useful when diabetes is suspected, particularly in oral candidosis, but does not investigate the usual associations of aphthous ulceration. A coagulation screen assesses haemostatic disorders and does not identify typical causes of recurrent aphthae.

Reference: Staines K, Sims C, Gibb J. Practice Pointer: Assessing oral ulcers and patches in primary care, Box 3: investigations for recurrent aphthous stomatitis. BMJ 2026;393:2025-085204. https://www.uclh.nhs.uk/patients-and-visitors/patient-information-pages/aphthous-ulcers