Reactive Perforating Collagenosis

Updated: Mar 07, 2017
  • Author: Rachel M Fisher, MBChB, MRCP; Chief Editor: Dirk M Elston, MD  more...
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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.



The major abnormality in reactive perforating collagenosis is focal damage to collagen and the elimination of the disrupted collagen through the epidermis. [1] A frequent association with pruritus, the tendency to the Koebner phenomenon and the distribution of lesions on trauma-prone areas provides evidence that superficial trauma (eg, scratching) may play a part in the etiology of reactive perforating collagenosis. Cold may precipitate the lesions, especially in the inherited form.

The acquired form usually occurs in patients with diabetes or chronic renal failure, especially those receiving dialysis. Other associations with systemic diseases, such as malignancy, have been reported.

Faver et al has proposed diagnostic criteria for the adult (acquired) form of reactive perforating collagenosis, as follows [2] :

  • Elimination of necrotic basophilic collagen bundles into a cup-shaped epidermal depression as seen in biopsy specimens

  • Umbilicated papules or nodules with a central, adherent keratotic plug

  • Onset of lesions after age 18 years




Inherited reactive perforating collagenosis is a rare disorder. Fewer than 50 cases of inherited reactive perforating collagenosis have been reported.

The acquired form of reactive perforating collagenosis is more common, occurring in as many as 10% of patients receiving maintenance hemodialysis. [3, 4]


No racial variations in the incidence of reactive perforating collagenosis are reported.


The sexual incidence of reactive perforating collagenosis is equal.


The inherited form of reactive perforating collagenosis usually presents in infancy or early childhood.

The acquired form of reactive perforating collagenosis occurs in adults. In a series of 22 patients with acquired reactive perforating collagenosis, the mean patient age at presentation was 56 years. [2]



The lesions of reactive perforating collagenosis are intensely itchy, leaving some scarring after resolution. The lesions of reactive perforating collagenosis often occur on a background of very itchy skin.