Reactive perforating collagenosis is an apparently rare dermatologic disturbance characterized by recurrent, umbilicated, papular lesions affecting various areas of the skin and by spontaneous disappearance of the lesions in a six- to eightweek period. New lesions often appear as older ones are involuting. It appears that the disease usually affects young children. The histologic pattern of the disease is distinct and is characterized by hematoxylinophilic changes in the collagen with eventual extrusion of the abnormal material via a mechanism known as epidermal elimination. The Koebner phenomenon is regularly observed. Superficial trauma appears to be a factor in precipitation of lesions, and since the disease may occur in siblings it is thought to be one of genetic origin. There are data concerning some 11 or 12 cases of reactive perforating collagenosis; this communication concerns two additional cases.
Weiner AL. Reactive Perforating Collagenosis. Arch Dermatol. 1970;102(5):540-544. doi:10.1001/archderm.1970.04000110056011