Disseminated superficial porokeratosis with dermal amyloid deposits: A case report and review of the literature.

Disseminated superficial porokeratosis with dermal amyloid deposits is exceptionally rare, with only 12 documented cases worldwide. The pathogenesis involves keratinocyte degeneration, resulting in amyloid deposition. A 76-year-old Chinese male presented with a 10-year history of multiple annular brown pruritic macules on the extremities and trunk, along with dense pruritic papules on the bilateral anterior tibial regions. Histopathological examination revealed cornoid lamella, dyskeratotic cells, and dermal amyloid deposits. Treatment with topical corticosteroids, 3% boric acid, and oral acitretin improved pruritus and pigmentation over 4 months; however, lesions recurred after discontinuation. Concomitant hyperuricemia (523 μmol/L) suggests a potential novel role of purine metabolism in amyloidogenesis, an association that has not been previously reported.