Background
Reactive perforating collagenosis is a rare skin disorder characterized by the transepidermal elimination of altered collagen through the epidermis. The 2 distinct forms of are an inherited form that manifests in childhood and an acquired sporadic form that occurs in adulthood.
The 4 primary perforating diseases are reactive perforating collagenosis, elastosis perforans serpiginosum, Kyrle disease, and perforating folliculitis, although whether perforating folliculitis is a primary perforating disease has been questioned, given that ruptured follicles are a feature of many infective conditions.
Some authors reserve the term reactive perforating collagenosis for the rare inherited form of the disease, preferring the term acquired perforating dermatosis for the acquired form. This article describes both inherited reactive perforating collagenosis and acquired reactive perforating collagenosis.