Core Revision
Revision aid, not clinical advice. This page is educational material written for exam preparation. It is not a substitute for the current guideline or for clinical judgement, and must not be relied on for the care of any individual. Always check up-to-date national guidance and verify independently before acting on anything here.
The Dermatology Reasoner
The MSRA loves a rash described in a single sentence. Learn to read the describing words that clinch a diagnosis, explore an interactive pattern library, work practice cases, and track the clues you have mastered as you go. Free, and it stays that way. Revision aid, not clinical advice — always check the current guideline before treating real patients.
Understand mode: the describing words that clinch a diagnosis — tap a card to see what each word means.
The mental model · read the describing words
Derm questions rarely give you a photo. They give you a sentence — and one or two adjectives in that sentence usually fit only one diagnosis. Train yourself to spot the clinching word, then confirm it with where the lesion is (extensor vs flexor, sun-exposed vs not) and who the patient is.
Below are the words that do the heavy lifting. Tap each to see which diagnosis it points to — every clue here is the verbatim description from the pattern library.
The clinching adjectives — tap to reveal what each one tells you.
Then confirm with site & who
- Extensor surfaces (elbows, knees) + silvery scale → think psoriasis; flexures (elbow/knee creases) + itch → think atopic eczema.
- Sun-exposed sites (face, scalp, backs of hands) → the skin cancers and actinic keratosis live here.
- Flexor wrists → the purple papules of lichen planus; finger web spaces → scabies burrows; a single dermatome → shingles.
- An atopic child, an elderly patient, days after a new drug — the “who” and “when” often decide it.
The emergencies you must never miss
Pattern library · the conditions, grouped by category
Every condition as a visual card with its classic clue. Tap a card for its features and management. Switch on Test me to be shown a clue and identify the diagnosis (multiple choice, mostly from the same category), with instant feedback and a running score. Filter by category to focus.
Management lines summarise guidance for exam revision — not for use in clinic.
MSRA & AKT Pattern · the give-away clues
- Silvery scale on extensors + nail pitting = psoriasis; itchy flexural = atopic eczema.
- Purple, polygonal, pruritic papules + Wickham’s striae = lichen planus.
- Herald patch then “Christmas-tree” = pityriasis rosea; annular with central clearing = tinea.
- Pearly rolled edge + telangiectasia = BCC (routine referral); a weighted 7-point checklist scoring 3 or more, or dermoscopy suggesting melanoma = suspected cancer pathway referral.
- Mucosal involvement + skin peeling after a drug = Stevens–Johnson/TEN — an emergency.
- Monomorphic punched-out erosions in eczema, unwell = eczema herpeticum — a same-day emergency (NICE CG57).
Reason · work the case from the describing words
You get the description a stem would give you. Reason to the diagnosis, then decide whether it’s an emergency — commit to each answer before you reveal it. That predict-then-check habit is what makes the pattern stick.
Read the describing words
Derm questions hinge on adjectives — well-demarcated, silvery, annular, targetoid, pearly. Train yourself to spot the one or two words that only fit one diagnosis, and where the lesion is (extensor vs flexor, sun-exposed vs not). Get those and you rarely need the photo.
Save your progress — and go further
Create a free account to get started with Core Revision; the full question banks are part of membership — the tool stays free either way.
Take this further
This tool is free. If you are preparing for the MRCGP AKT, the full course puts the same reasoning into exam-style questions: a question bank with Core Lens and Deep Dive explanations, a Core Calendar revision plan built around your exam date, and Core Compass to show you which topics need you next.
Preparing for the MSRA instead?
Questions? Email admin@corerevision.com
Core Revision Ltd, registered in England & Wales, company no. 16956954. Registered office: 71–75 Shelton Street, Covent Garden, London, WC2H 9JQ.
© 2026 Core Revision Ltd. All rights reserved.
Core Revision Ltd is an independent educational platform and is not affiliated with the RCGP.
Written by practising UK GPs for exam revision. Sources are cited on this page and corrections are logged. Education only — always confirm against current guidance. Core Revision is an independent revision resource.