Pinch purpura is diagnostic of –

In primary systemic amyloidosis amyloid deposition occurs in the wall of the blood vessels, this leads to an increase in skin fragility. As a result, petechiae and purpura develop in clinically normal skin as well as in lesional skin following minor trauma. Therefore the skin lesions in case of primary systemic amyloidosis are called pinch purpura. These lesions are pink in colour and translucent. Common locations are Face (especially the periorbital and perioral regions) Flexural areas.