Pseudoxanthoma Elasticum-Like Changes:Associations- and Underlying Mechanisms.

Pseudoxanthoma elasticum (PXE) is an inherited disorder characterized by degradation and fragmentation of elastic fibers and calcium depos- its in the dermis. It clinically manifests as yellow papules or plaques in a cobblestone distribution or "plucked-chicken skin" appearance on the lateral neck and/or flexural areas. In addition, it can also affect the eyes, cardiovascular, and gastrointestinal systems. It is considered as the prototype of ectopic heritable mineralization disorders, usually diagnosed in the second decade of life. The majority of patients are sporadic but recessive, but pseudodominant autosomal forms have been described as well. Mutations affecting the ATP-binding cassette subfamily C member 6 (ABCC6) gene or gamma-glutamyl carboxylase (GGCX) gene lead to PXE. Accumulating evidence in the literature has found that numerous disorders may demonstrate cutaneous PXE-like clinical and/or histologic features without any other systemic evidence of PXE or any genetic documentation of inherited mutations. In this review, we aimed to highlight all the disorders that were reported to exhibit PXE-like clinical and/or microscopic changes and to discuss possible underlying mechanisms leading to such an overlap.