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AT-A-GLANCE
Acquired perforating disorders represent a group of separately identified cutaneous disorders that occur most often in the setting of chronic renal disease or diabetes mellitus.
The previously recognized Kyrle disease (KD), acquired elastosis perforans serpiginosa (AEPS), acquired perforating collagenosis (APC), and perforating folliculitis (PF) are now classified under the umbrella term of acquired perforating dermatosis.
Lesions present as umbilicated papules and/or nodules with a central keratotic plug or crust distributed preferentially on extensor surfaces of the extremities.
Histopathologic examination of lesional skin demonstrates invagination of the epidermis with extrusion of dermal material (collagen, elastin, and/or fibrin) through the cup-shaped epidermal depression.
Treatment is challenging with no universally effective therapy, and patients often exhibit a chronic course.
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The perforating disorders are a group of conditions characterized by the transepidermal elimination of connective tissue elements. Although this finding may be the primary manifestation of familial or acquired systemic conditions (ie, chronic renal failure, diabetes mellitus), the perforation of dermal elements also may be seen as a secondary component to other primary dermatoses (eg, perforating granuloma annulare, gout, perforating pseudoxanthoma elasticum) (Table 71-1). Rare familial primary perforating disorders typically present in childhood and are characterized histopathologically by the transepidermal elimination of collagen (reactive perforating collagenosis) or elastic fibers (elastosis perforans serpiginosa). Similar adult-onset nonfamilial/acquired lesions are most commonly associated with chronic kidney disease and diabetes mellitus. These cases were originally given various appellations within the medical literature, complicating the subject matter (Table 71-2). Eventually, comprehensive review of the literature concluded that 4 separate clinicopathologic entities characterized the adult-onset acquired primary perforating disorders: Kyrle disease (KD), acquired perforating collagenosis (APC), perforating folliculitis, and acquired elastosis perforans serpiginosa (AEPS).1-4 Further studies, however, have reported more clinicopathologic similarities than differences among these acquired conditions, in particular, a varied composition of extruded contents (ie, collagen, elastin fibers, fibrin) from lesion to lesion in the same patient. This has resulted in some authors advocating for a combined designation of acquired perforating dermatosis (APD).5,6 Although the use of this unified designation is encouraged, an acknowledgment of the clinical and histopathologic manifestations of these 4 described conditions is important for understanding the spectrum of findings as well as possible correlations with systemic disease (Table 71-3).
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