D-penicillamine elastosis perforans serpiginosa: description of two cases and review of the literature.

Long term D-penicillamine (DPA) therapy to treat Wilson disease can induce elastosis perforans serpiginosa (EPS), a very rare degenerative skin disease characterized by a transepidermal elimination of elastic fiber aggregates. The iatrogenous disease depends on DPA capacity to chelate copper and cause its depletion. Lysyl-oxidase is a copper dependent enzyme crucial to the dermal elastic fiber cross-linking, which is strongly affected by DPA copper depletion. Direct binding of the drug to collagen precursors also affects elastic fiber assemblage and maturation. The abnormal elastin accumulates into the middle dermis and produces a characteristic bramble brush or "lumpy-bumpy" appearance. In this way it acts as a foreign body and is progressively extruded through the epidermis. Clinically, the disease presents with multiple firm keratotic papules and nodules arranged in annular plaques over the neck, axillae, antecubital fossae, and forearms. The rarity of the disease frequently causes misdiagnoses and the process continues unabated causing concerns about systemic elastopathy.