Pseudoxanthoma elasticum

Pseudoxanthoma elasticum

This is the classical inherited connective tissue disor-der affecting the elastic structures in the bodyamost obviously in the skin, blood vessels and eyes.

Cause

It has recently been found that both the dominantly and recessively inherited types are a result of muta-tions in a gene (on chromosome 16p13.1) encoding for a transmembrane transporter protein, which is a member of the ABC transporters superfamily. It is still not clear how this causes the disease.

Pathology

The elastic fibres in the mid-dermis become swollen and fragmented; their calcification is probably a sec-ondary feature. The elastic tissue of blood vessels and of the retina may also be affected.

Clinical features

The skin of the neck and axillae, and occasionally of other body folds, is loose and wrinkled. Groups of small yellow papules give these areas a ‘plucked chicken’ appearance (Fig. 21.8). Breaks in the retina show as angioid streaks, which are grey poorly defined areas radiating from the optic nerve head. Arterial involvement may lead to peripheral, coron-ary or cerebral arterial insufficiency.

Complications

The most important are hypertension, recurrent gut haemorrhages, ischaemic heart disease and cerebral haemorrhage.

Diagnosis and treatment

The diagnosis is made clinically and confirmed by the histology. There is no effective treatment.