 The human body has 206 bones that give it shape and
strength.
The place where two bone meet is called "joint".
At the joints, the bones are covered by tissues called "cartilage".
Joints have a clear fluid in them called "synovial fluid" which play the role of
lubrication of the joint and allows it to move smoothly with very little
friction.
When the tissues of a joint are injured or affected by a disease, they may
swell and become red and hot causing pain; this known as join inflammation or
"arthritis". The term "gout" traditionally refers to the painful
arthritis attacks.
There is more than 200 types of arthritis and gout represents a type of
arthritis which affects 1 out of every 20 patients who have arthritis.
| Definition |
Gout has the unique distinction of being one of the most
frequently recorded medical illnesses throughout history.
Gout (also called metabolic arthritis) is often related to an inherited
abnormality of the uric acid metabolism.
Uric acid is a breakdown product of purines, that are part of many foods
we eat. An abnormality in handling uric acid can cause attacks of
painful arthritis (gout), kidney stones, and blockage of the kidney
tubules with uric acid crystals, leading to kidney failure.
On the other hand, some patients may only develop elevated blood uric
acid levels (hyperuricemia) without arthritis or kidney problems , in
this case; monosodium urate crystals are deposited on the articular
cartilage of joints and in the particular tissue like tendons.
This provokes an inflammatory reaction of these tissues. These deposits
often increase in size and burst through the skin to form sinuses
discharging a chalky white material.
Gout is nine times more common in men than in women. It predominantly
attacks males after puberty, with a peak age of 75. In women, gout
attacks usually occur after menopause.
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| Signs and symptoms |
The Gout, causes the excruciating pain and swelling of joints which
are the major symptoms of the disease.
The classic picture is:
►Excruciating and sudden pain
►Stiffness in the joint.
►Low-grade fever may also be present
►Warmness
►Redness
►Swelling
The patient usually suffers from two sources of pain:
1-The crystals inside the joint cause intense pain whenever the affected
area is moved.
2-The inflammation of the tissues around the joint also causes the skin
to be swollen, tender and sore if it is even slightly touched. For
example, a blanket draping over the affected area could cause extreme
pain.
Gout usually attacks one joint at a time, while other arthritic
conditions, such as systemic lupus and rheumatoid arthritis, usually
attack multiple joints simultaneously.
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Uric acid crystals can deposit in tiny fluid-filled sacs
(bursae) around the joints. These urate crystals can incite inflammation
in the bursae leading to pain and swelling around the joints, a
condition called bursitis. In rare instances, gout leads to a more
chronic type of joint inflammation which mimics rheumatoid arthritis.
In chronic (tophaceous) gout, nodular masses of uric acid crystals
(tophi) deposit in different soft tissue areas of the body. Even though
they are most commonly found as hard nodules around the fingers, at the
tips of the elbows, and around the big toe, tophi nodules can appear
anywhere in the body. They have been reported in unexpected areas such
as in the ears, vocal cords, or around the spinal cord.
Gout usually attacks the big toe (approximately 75% of first attacks),
however it can also affect other joints such as the ankle, heel, instep,
knee, wrist, elbow, fingers, and spine. In some cases the condition may
appear in the joints of the small toes which have become immobile due to
impact injury earlier in life, causing poor blood circulation that leads
to gout.
Patients with longstanding hyperuricemia can have uric acid crystal
deposits called tophi (singular: tophus) in other tissues e.g. the helix
of the ear. Uric acid stones can form as one kind of kidney stone in
some occasions.
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| Stages of gout |
Gout has four distinct stages:
1st stage-Asymptomatic:
Purine is a chemical compound that is present in all of the cells of the
body. Extra purine is secreted out of the body in the urine in form of
uric acid.
At times, there may be abnormally high levels of uric acid in blood,
this condition is called "Hyperuricemia". Plasma uric acid level
increases due to extra purine secreted out in the urine in form of uric
acid, but there are no symptoms. This condition is called
"Hyperuricemia".
2nd stage-Acute:
When there is a lot of uric acid, it begins to form
crystals and deposits under the skin, forming a lump that can sometimes
be felt on the outside of the body. The first attack of gout marks the
second, mild attacks usually go away quickly, whereas severe attacks can
last days or even weeks.
The immune system, the body's defense against sickness, realizes that
the crystals should not be there and starts attacking them. This is what
cause joint pain, tenderness which can be intense so that even a blanket
touching the skin over the affected joint can be unbearable.
Acute gout attacks are characterized by a rapid onset of pain in the
affected joint followed by warmth, swelling, and reddish discoloration.
This condition is called "Padogra" which affected 3 of each 4 patients
who have gout. Patients can develop fever with the acute gout attacks.
These painful attacks usually subside in hours to days, with or without
medication. In rare instances, an attack can last for weeks.
3rd stage-Intercritical:
After the initial attack, the person enters the
intercritical stage or symptom-free interval that may last months or
even years. Most gout patients have their second attack within 6 months
to 2 years from their initial episode.
4th stage-Chronic:
In the last or chronic stage, gout attacks become
frequent and become polyarticular (affecting multiple joints at one
time). Large tophi can also be found in many joints. In advanced cases
of chronic gout, the extra uric acid may also deposits in the kidney
leading to kidney stones and hypertension.
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| Pathogenesis |
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Uric acid ------►Crystals------►Crystals deposits in joint------►Joint inflammation
Purines can be generated by the
body itself (via the breakdown of cells in normal cellular turnover) or can be
ingested in purine-rich foods (e.g. seafood, beer). Most people with gout,
however, do not produce more than the normal amount of uric acid. Instead, most
people with gout tend to be underexcretors. The kidney is responsible for about
one third of uric acid excretion, with the gut responsible for the rest. It may
be possible that defects in the kidney that may be genetically determined are
responsible for the predisposition of individuals for developing gout.
Secondary gout and hyperuricemia can be promoted by:
►Eating too many food rich of purine such as: shellfish, organ meats:
liver, kidney and brain.
►Dried beans, peas and anchovies are also rich
in purines.
►Drinking too much alcohol interferes with the body's ability to get rid
of extra uric acid.
►Exposure to high levels of lead.
►Being overweight.
►Polycythaemia
►Certain diseases lead to excessive production of uric acid in the body
e.g. of these diseases include
Leukemia,
diabetes, lymphomas, and
hemoglobin disorders.
►Certain drugs: which interferes the ability of kidney to excrete uric
acid, such as thiazide diuretics, low-dose aspirin, and tuberculosis
medications (pyrazinamide and ethambutol) can also cause gout.Patients who are on
cyclosporine (medication used in transplantation ot prevent the organs
rejection).
Gouty arthritis attacks can be precipitated by
dehydration, injury,
fever, heavy eating, heavy drinking of alcohol, and recent surgery.
Gout arises directly from elevated levels of uric acid within the blood.
The amount of uric acid within the body is determined by the balance
between the amount being produced and the amount being excreted.
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