Dermoscopy of An Acquired Perforating Dermatosis: A Case-Report

Primary perforating dermatoses are a group of skin disorders characterized by transepidermal elimination of dermal material and include reactive perforating collagenosis, elastosis perforans serpiginosa, perforating folliculitis, and acquired perforating dermatosis. Acquired perforating dermatosis is most common in elderly patients with diabetes mellitus or chronic renal failure. Diagnosis is traditionally made on the basis of clinical and histological findings, but dermocopy can also make a valuable diagnostic contribution. Indeed, the pattern seen in acquired perforating dermatosis consists of a central keratotic plug surrounded by a variable number of concentric structures: a whitish area also known as the "white collar sign" and a pinkish area, both of which may contain a vascular pattern, and peripheral pigmentation. The dermoscopic appearance may also change over the course of the disease, with the vascular pattern being progressively replaced by a reddish-dark area, and finally with the central crust falling away and the lesion taking on a scarred appearance. We report here a case of acquired perforating dermatosis in an unbalanced diabetic patient, 73 years old, whose dermoscopic appearance revealed 4 concentric zones and whose histology showed transepidermal elimination of collagen fibers.