| Pseudoxanthoma
elasticum (PXE) is a systemic disease. The appearance
of the skin is due to calcific degeneration of the elastic tissue
of the dermis. Calcific degeneration of the large arteries of the
extremities and gastrointestinal bleeding also occur. Skin biopsy
can be done to establish the diagnosis. Ocular
findings include (1)
peau d’orange pigmentary change (areas
of fundus mottling caused by multiple, confluent, yellowish lesions
at the level of the RPE, generally most prominent temporally), (2)
reticular pigmentary dystrophy of the macula, focal
atrophic RPE lesions in the midperiphery (resembling
scars seen in the presumed ocular histoplasmosis syndrome), (3)
crystalline bodies
(in midperiphery or juxtapapillary area in about 75% of cases and
always associated with RPE atrophy— occasionally appearing
as a “comet tail”
and evident in this patient), and (4) optic
disc drusen. Inheritance of PXE can be autosomal
dominant or recessive. |
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