Imiquimod therapy for elastosis perforans serpiginosa.

A 14-year-old girl was first seen with an 8-month history of an asymptomatic “rash” on her chin and a “wart” on her right hand. At physical examination, she had several pink papules coalescing into annular and arcuate plaques on the central aspect of her chin (Figure 1). She was also noted to have a single flesh-colored verrucous papule on her right palm, which was treated with liquid nitrogen cryotherapy. A biopsy of her chin was performed to rule out annular verruca plana. This biopsy specimen demonstrated narrow channels in the epidermis filled with orthokeratotic and parakeratotic cells, refractile eosinophilic elastic fibers extending into the papillary dermis, and a few neutrophils (Figure 2). An elastic stain demonstrated an increased concentration of clumped and thickened elastic fibers in the middle dermis extending to the epidermis. These findings were consistent with the clinical diagnosis of elastosis perforans serpiginosa (EPS). After careful review of the patient’s medical history and medication intake and a thorough evaluation for comorbid systemic disorders, she was diagnosed as having idiopathic EPS.