A case is presented exhibiting an unusual reaction of the skin to superficial trauma. In response to minor trauma, certain changes take place within the papillary layer of the corium characterized by affinity of the connective tissue for hematoxylin. Secondary changes of the overlying epidermis eventually lead to complete elimination of the altered connective tissue.
Mehregan AH, Schwartz OD, Livingood CS. Reactive Perforating Collagenosis. Arch Dermatol. 1967;96(3):277-282. doi:10.1001/archderm.1967.01610030055009