Excerpt from Pseudoxanthoma Elasticum

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Background

Pseudoxanthoma elasticum (PXE) is an inherited systemic disease characterized by changes in the elastic tissue of the skin. Pseudoxanthoma elasticum mainly affects the skin, eyes, heart, and gastrointestinal (GI) system.

The cutaneous and ocular findings of pseudoxanthoma elasticum are referred to as Grönblad-Strandberg syndrome. The cutaneous changes in pseudoxanthoma elasticum are distributed in the intertriginous areas of the body, such as the flexural regions of the extremities, in the folds of the skin at the sides of the neck, the cubital and popliteal fossa, the axilla, in the creases of the groin, and periumbilical area. Typical lesions are described as yellow waxy papules associated with loose and thickened skin. Pseudoxanthoma elasticum may be autosomal dominant or autosomal recessive.

Other systemic findings in pseudoxanthoma elasticum include intracranial aneurysms, claudication, hypertension, cerebrovascular accidents, cerebral ischemia, myocardial infarction, and GI hemorrhage.

Pathophysiology

The lesions in pseudoxanthoma elasticum are characterized by increased amounts of elastic tissue that have the tendency to become calcified. The controversy has focused on the nature of the elastic tissue and whether the elastic tissue is abnormal from the time of synthesis or normal from the outset with subsequent degeneration.

The reason why elastic fibers become calcified in pseudoxanthoma elasticum remains unknown. Investigators have found polyanions within elastic fibers in both clinically affected and nonaffected dermis by using histochemical and electron microscopy techniques. This polyanionic material may explain the increased affinity of elastic fibers for calcium and may be a factor in the pathogenesis of the disease.

Frequency

United States

The reported prevalence of pseudoxanthoma elasticum is 1 in 160,000 births.

Mortality/Morbidity

Patients with pseudoxanthoma elasticum are at risk for loss of central vision, subarachnoid hemorrhage, severe GI hemorrhage, chronic peripheral occlusive disease, and cerebrovascular insufficiency. Subarachnoid hemorrhage has been a major cause of death.

Sex

Females are affected with pseudoxanthoma elasticum twice as often as males.

Age

Patients with pseudoxanthoma elasticum usually are diagnosed in the third to fourth decades of life.

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