Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
The connective tissues are the structural portions of the body
that essentially hold the body cells together. These tissues form a
framework or matrix for the body. The connective tissues are composed
of two major structural molecules, collagen and elastin. There are many
different collagen protein types which vary in abundance depending on
body area. Elastin is another protein which has the capability of
stretching and returning to original length like a spring.
Pseudoxanthoma elasticum (PXE) is a rare disorder of degeneration
of the elastic fibers with tiny areas of calcification in the skin,
back of the eyes (retinae), and blood vessels. Interestingly, while
elastin is the major component of ligaments (tissues which attach
bone to bone), the ligaments are not apparently affected by PXE.
How is pseudoxanthoma elasticum inherited?
PXE is inherited from the parents, either as an autosomal
recessive or as an autosomal dominant trait. Identification of the
gene responsible for PXE can facilitate the determination of the
exact patterns of inheritance. Pseudoxanthoma elasticum is an inherited disorder
of elastin.
What are symptoms of pseudoxanthoma elasticum?
PXE typically causes yellow-white small raised areas in the skin
folds, often appearing in the second or third decades of life. These
skin abnormalities frequently appear on the neck, armpits, and other
areas that bend a great deal (referred to as flexure areas). The face
is not affected by PXE. The doctor can often see abnormalities in the
back of the eye (retinae) called angioid streaks, which are tiny
breaks in the elastin-filled tissue there. These eye abnormalities
can lead to blindness.
Other areas that can be affected in PXE include the heart which
can be affected by atherosclerosis and mitral valve prolapse. Small
blood vessels are abnormally fragile in patients with PXE because the
blood vessel walls contain elastin and are weakened. This can lead to
abnormal bleeding in such areas as the bowel and, very rarely, the
uterus. Impairment of circulation to the legs can lead to pains in
the legs while walking (claudication).
Peripheral vascular disease (PVD) refers to diseases of the blood vessels (arteries and veins) located outside the heart and brain. While there are many causes of peripheral vascular disease, doctors commonly use the term peripheral vascular disease to refer to peripheral artery disease (peripheral arterial disease, PAD), a condition that develops when the arteries that supply blood to the internal organs, arms, and legs become completely or partially blocked as a result of atherosclerosis. Peripheral artery disease symptoms include: intermittent claudication, rest pain, numbness in the extremities, and more. Treatment for peripheral artery disease include: lifestyle measures, medication, angioplasty, and surgery.
Peripheral vascular disease (PVD) refers to diseases of
the blood vessels (arteries and veins) located outside the heart and brain.
While there are many causes of peripheral vascular disease, doctors commonly use
the term peripheral vascular disease to refer to peripheral artery disease (peripheral
arterial disease, PAD), a condition that
develops when the arteries that supply blood to the internal organs, arms, and legs become
completely or partially blocked as a result of atherosclerosis.
What is atherosclerosis?
Atherosclerosis is a gradual process whereby hard
cholesterol substances
(plaques) are deposited in the walls of the arteries.
Cholesterol plaques cause
hardening of the artery walls and narrowing of the inner channel (lumen) of the artery.
The atherosclerosis process begins early in life (as early as teens in some
people). When atherosclerosis is mild an...