A skin biopsy in a patient with pseudoxanthoma elasticum (PXE) may show characteristic changes in elastic fibers.


Patient selection: possible pseudoxanthoma elasticum without characteristic skin lesions


Site selection: flexural skin or scar


Site exclusion: hypertrophic scar or keloid (do not contain as many elastic fibers)


Special stain: Verhoeff-van Gieson and von Kossa stains


The diagnostic finding is the presence of clumping and fragmentation of elastic fibers in the middle and deep dermis (reticular dermis).



• The presence of diagnostic changes supports the diagnosis of pseudoxanthoma elasticum.

• The absence of the finding does not exclude it since it may be site and observer dependent.

• The more sites that are sampled the greater the chances of finding the feature.

• A skin biopsy can also be helpful in identifying disorders like solar elastosis that may be clinically confused with the skin lesions of PXE.



• The change shows a low sensitivity but high specificity.

• Testing for gene mutations in ABCC6 may be more cost effective for the diagnosis of PXE while a skin biopsy allows consideration of disorders in the differential diagnosis.


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