Pinch purpura is seen in?

Ans. (a) Primary systemic amyloidosis(Ref: Harrison 18th/chapter 112)Cutaneous lesions associated with primary systemic amyloidosis are often pink in color and translucent.Common locations are face, especially periorbital and perioral regions, and flexural areas.On biopsy, homogeneous deposits of amyloid are seen in the dermis and in the walls of blood vessels;These deposits lead to an increase in vessel wall fragility.As a result, petechiae and purpura develop in clinically normal or abnormal skin following minor trauma, hence the term pinch purpura.