Que SKT, Fraga-Braghiroli N, Grant-Kels JM, Rabinovitz HS, Oliviero M, Scope A. A pink papule on the back of an 82-year-old man: an example of the buttonhole sign on reflectance confocal microscopy. Dermatol Pract Concept [Internet]. 2016 Jul. 31 [cited 2026 Apr. 25];:1-2. Available from: https://www.dpcj.org/index.php/dpc/article/view/dermatol-pract-concept-articleid-dp0603a01