Elastosis perforans serpiginosa.

A 41-year-old white man with Down syndrome presented with a slightly pruritic, papular eruption on bilateral forearms of several years' duration. Physical examination revealed multiple 2- to 3-mm keratotic, umbilicated pink papules in an annular configuration distributed symmetrically on the flexural surfaces of the forearms (Figure 1). The skin surrounding these papules was noted to be hyperpigmented and somewhat atrophic. The remainder of his skin examination was unremarkable. A shave biopsy of 1 papule was performed and stained with hematoxylin-eosin. Hematoxylin-eosin-stained sections showed clumps of bright red fibers being extruded through an acanthotic epidermis with a central invagination (Figure 2). Verhoeff-van Gieson stain confirmed these fibers to be elastin (Figure 3). Elastosis perforans serpiginosa was diagnosed.