Reactive perforating collagenosis occurred in a young girl. A typical linear skin lesion was induced by a needle scratch on her forearm on two occasions. This experiment supports Mehregan's hypothesis of relationship between superficial trauma and the occurrence of skin lesions.
Bovenmyer DA. Reactive Perforating CollagenosisExperimental Production of the Lesion. Arch Dermatol. 1970;102(3):313–317. doi:10.1001/archderm.1970.04000090075012