Cutaneous Amyloidosis — SCE Dermatology MCQ

Instant feedback + full explanation. One question, done properly.

HardInflammatory DermatosesCutaneous AmyloidosisSCE Dermatology

A 55-year-old woman has localised cutaneous amyloidosis. She has pruritic brown rippled papules on her upper back (macular amyloidosis) with areas of lichenoid papules on her shins (lichen amyloidosis). What type of amyloid is deposited?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: B — Amyloid derived from keratin intermediate filaments (AK amyloid — degenerated keratinocyte-derived filamentous material)

Primary localised cutaneous amyloidosis (macular and lichen subtypes) involves deposition of amyloid derived from keratin intermediate filaments — designated AK (amyloid-keratin) amyloid. This is formed from filamentous degeneration of keratinocyte cytoskeleton, with damaged keratinocytes dropping their keratinous material into the papillary dermis. This is distinct from systemic amyloidosis (AL from immunoglobulin light chains in myeloma, AA from serum amyloid A in chronic inflammation, ATTR from transthyretin in familial/senile). Localised cutaneous amyloidosis is benign — no systemic amyloid investigation is needed. Treatment addresses pruritus: potent topical corticosteroids, topical Tacrolimus, DMSO, and antipruritic agents.

Reference: BAD 2019; Dermatopathology