Late-onset focal dermal elastosis: an uncommon mimicker of pseudoxanthoma elasticum.

Late-onset focal dermal elastosis is a rare disorder that presents clinically with the development of small white-to-yellow papules simulating pseudoxanthoma elasticum (PXE) in otherwise healthy adults in the seventh through ninth decades. It is characterized histopathologically by foci of increased normal-appearing elastic tissue in the reticular dermis. The disorder lacks any of the systemic complications of PXE and clinically resembles several other elastic tissue disorders that mimic PXE. We report two cases of late-onset focal dermal elastosis. The first is of a 75-year-old female who presented with symmetrically distributed, 2-5 mm white-to-yellow, discrete and coalescing, non-follicular papules on the posterolateral neck, anterior chest and axillae. The second case involves a 39-year-old female who presented with asymptomatic flesh-colored lesions on the posterior neck, back, antecubital and popliteal fossae, thighs, forearms and wrists. Skin biopsies in each case revealed aggregates of elastic fibers in the reticular dermis without calcification. The differential diagnosis of clinical and histopathologic imitators of PXE is discussed.