Actinic keratosis — SCE Dermatology MCQ

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ModerateSkin oncologyActinic keratosisSCE Dermatology

A 70-year-old man has multiple rough erythematous scaly macules on a bald scalp with widespread actinic damage. None are indurated, tender, rapidly enlarging or ulcerated. He prefers treatment for the whole affected field rather than repeated cryotherapy. What is the most appropriate treatment?

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Correct answer: A — Field treatment with topical 5-fluorouracil

The correct answer is A, field treatment with topical 5-fluorouracil. This patient has multiple, non-suspicious actinic keratoses (no induration, tenderness, rapid growth or ulceration, which would raise concern for SCC transformation) across a widely sun-damaged scalp, representing field cancerisation rather than isolated lesions. In this situation UK dermatology guidance recommends field-directed therapy over lesion-by-lesion cryotherapy, and topical 5-fluorouracil is a standard first-line field treatment that targets clinically visible and subclinical dysplastic keratinocytes across the whole area. It is applied as a course (commonly once or twice daily for several weeks) and produces an inflammatory reaction as abnormal cells are destroyed, which is expected and should be explained to the patient in advance.

Reference: https://www.nice.org.uk/guidance/conditions-and-diseases/skin-conditions