Reactive perforating collagenosis
What is reactive perforating collagenosis?
Reactive perforating collagenosis is a rare skin disorder in which abnormal collagen fibres extrude through the epidermis (outer layer of skin).
Two distinct forms of the disease have been identified:
- Inherited – manifests in infancy or early childhood
- Acquired – occurs in adulthood, usually in patients with diabetes or chronic renal failure, especially those receiving dialysis
The other major perforating disease is elastosis perforans serpiginosa.
Who gets reactive perforating collagenosis?
The inherited form is a very rare condition with less than 50 cases reported in literature worldwide. Acquired reactive perforating collagenosis is more common and occurs in approximately 10% of patients receiving maintenance haemodialysis.
What causes reactive perforating collagenosis?
The cause of abnormal collagen extruding through to the epidermis is unknown but lesions appear in response to superficial trauma such as scratching and are aggravated by cold weather. This is particularly the case in the inherited form. The mode of inheritance is not clear as reports of affected families reveal autosomal dominant and autosomal recessive inheritance as well as sporadic cases.
In addition to affecting people with chronic renal failure and diabetes, acquired reactive perforating collagenosis has been reported in patients with hypothyroidism (underactive thyroid gland), hyperparathyroidism (overactive parathyroid glands), liver disease, and lymphoma.
What are the signs and symptoms?
In the inherited form, painless 1 to 6 mm diameter keratotic papules develop on the extensor surface of the hands, the elbows, and the knees following superficial trauma. The lesions start off as pin-sized lesions that over 3-5 weeks grow to a papule of about 6mm. These resolve spontaneously in 6-8 weeks leaving residual minor scarring. Lesions recur throughout life into adulthood. In some cases, cold weather conditions can trigger the recurrence of lesions.
In acquired reactive perforating collagenosis keratotic lesions develop on the trunk and extremities and are commonly associated with pruritus (itching). Lesions are often but not necessarily related to superficial trauma.
How is it diagnosed?
Acquired reactive perforating collagenosis is diagnosed by clinical features Reactive perforating collagenosis pathology feautres on biopsy are characteristic.
What treatment is available?
Lesions are usually self-healing without any treatment but often recur. Treatments that have been used to treat and reduce lesions include: