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Inherited connective tissue disorder characterized by
progressive calcification and fragmentation of elastic fibers in skin,
retina, and cardiovascular system leading to multiple vascular lesions
caused by medial calcification of medium-sized and major arteries. Severe
cardiovascular complications must be expected.
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Pseudoxanthoma Elasticum; PXE.
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First described by Ester Elizabeth Groenblad, a Swedish
ophthalmologist, and James Victor Strandberg, a Swedish dermatologist, in
1929.
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Incidence in the general population is estimated at
1:100,000. Male-to-female ratio is 2:1.
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Various patterns: two autosomal dominant forms
(type II, characterized by isolated skin manifestations) and two autosomal recessive forms
(type I, represents 95% of patients),
caused by mutations in the ABCC6 gene
(adenosine triphosphate-binding cassette, subfamily C, member 6) probably
mapped on 16p13.1.
Sporadic cases have also been observed.
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Unknown; An abnormal secretion of glycosaminoglycans by
fibroblasts may result in coating of the elastic fibers. Another hypothesis is the
presence of an abnormal protease that renders elastic fibers prone to
calcification.
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Based on the clinical findings of skin lesions,
which are almost always
present, and start in the teen years at the neck, progressing to armpits,
elbows, and groins and consisting of yellow papules, followed by visual
impairment at approximately 25 years of age, but never leading to blindness (peripheral
vision is preserved).
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Features involve skin (small, yellow papules in
mouth, neck, axilla, elbow, groin, and periumbilical region; orange peel
appearance, elastosis perforans serpiginosa), eyes (angioid streaks of the
retina in Bruch membrane, macular degeneration, decreased visual acuity,
myopia, blue sclerae, retinal hemorrhages), heart and vessels (mitral valve prolapse,
angina pectoris from
premature occlusive vascular disease, arteriosclerosis, medial calcification
of medium-sized and major arteries, diminished or absent peripheral pulses,
claudication, congestive heart failure, restrictive cardiomyopathy
myocardial infarction), gastrointestinal system (gastrointestinal hemorrhage,
gastric and duodenal microaneurysms, arteriovenous malformations), skeleton (pectus
deformities, kyphosis, scoliosis), and central nervous system
(stroke, cerebral hemorrhage calcification of falx cerebri).
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Assess for occult blood loss (red
blood cell count, fecal test, urine analysis). Evaluate cardiovascular function
(clinical, ECG, Doppler ultrasonography, echocardiography). Evaluate
ophthalmologic lesions (clinical, ophthalmologic examination).
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Vascular risk is major and requires appropriate
perioperative cardiac monitoring. Arterial blood pressure should be strictly controlled,
but invasive monitoring is often difficult because of frequent loss of peripheral
pulses and calcifications of the arteries.
Avoid arterial hypotension.
Regional anesthesia is not
contraindicated, but vascular resistance response to sympathetic blockade is
unpredictable. Renal failure may occur, so kidney function should be assessed.
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When choosing an anesthetic drug,
consider these patients as suffering from coronary and
arteriosclerosis. Postoperative hypocoagulation should be considered.
Subacute bacterial endocarditis prophylaxis may be required if mitral valve
prolapse is associated with mitral regurgitation or mitral stenosis is present.
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Ehlers-Danlos Syndrome (EDS): Characterized by joint hypermobility,
hyperelasticity of the skin, and generalized tissue fragility including
blood vessels and skin. The blood vessels may rupture even ...