Acquired reactive perforating collagenosis associated with diabetes mellitus: eight cases that meet Faver's criteria

Reactive perforating collagenosis (RPC) is characterized by umbilicated pap ules with a central adherent keratotic plug, Histologically, this condition shows transepidermal elimination of altered dermal collagen bundles into a cup-shaped epidermal depression. The present paper describes eight patient s with associated diabetes mellitus who meet the diagnostic criteria for th e acquired form of RPC (ARPC). Although half of these patients underwent di alysis, the lesions did not tend to develop after dialysis, Pruritus and th e Koebner phenomenon were common, and histologically a microvasculopathy wa s noted in the dermis of all patients. We speculate that this disease is tr iggered by a cutaneous response to superficial trauma. Furthermore, this re sponse acts synergistically with vasculopathy in the dermis, primarily in t he case of diabetes mellitus, A secondary sign of ARPC may be degenerated c ollagen fibres as a result of transepidermal elimination.