Sickle cell disease,

Sickle cell disease
Sickle cell disease is the most common of the hereditary
blood disorders . It occurs almost exclusively among black
Americans and black Africans.
Sickle cell disease in black Americans occurs in about 1 in
500 live births.
The first account of what was then called sickle cell anemia in
the medical literature was in 1910. James B. Herrick, a
Chicago physician, described the symptoms of a 20-year-old
black male student from the West Indies. The man had
reported "shortness of breath, palpitations , and episodes of
icterus [ yellow eyes ]. He had an anemia." Dr. Herrick described
the patient's blood smear as showing "thin, sickle-shaped and
crescent-shaped red cells."
Red blood cells deliver oxygen to working or active tissues. In
the lungs , hemoglobin (the molecule in the red blood cell)
takes on oxygen and, at the same time, releases carbon
dioxide. This process is called oxygenation. At the tissue level,
this activity is reversed. The same hemoglobin molecule
releases oxygen and takes on carbon dioxide. This process is
called deoxygenation.
In sickle cell disease, certain red blood cells become
crescent-shaped (the sickle cell Dr. Herrick described).
These abnormal red blood cells, carrying an abnormal
hemoglobin known as hemoglobin S , are fragile.
A person who has sickle cell disease can become more likely
to get infections because the damaged cells eventually clog
the spleen.
A severe attack, known as sickle cell crisis, can cause pain
because blood vessels can become blocked or the defective
red blood cells can damage organs in the body.
There is also an impairment in oxygentation from the
abnormal hemoglobin S.
Sickle Cell Disease Causes
Sickle cell disease results from mutation, or change, of certain
types of hemoglobin chains in red blood cells (the beta
hemoglobin chains).
The changes in the building of normal hemoglobin result in the
abnormal hemoglobin of sickle cell disease. These mutated
molecules do not have the smooth motion needed for
oxygenation and deoxygenation. When the oxygen
concentration in the blood is reduced, the red blood cell
assumes the characteristic sickle shape. This causes the red
blood cell to be stiff and rigid, and stops the smooth passage
of the red blood cells through the narrow blood vessels.
It does not take much imagination to see sharp-end "sickled"
red cells stacking up in narrow blood vessels known as
capillaries. When this happens, red blood cells are not able to
carry oxygen to tissues, and tissue cell injury or death occurs.
Someone with sickle cell disease would be experiencing pain
with this process-the sickle cell crisis.

Sickle Cell Disease Symptoms
The sites most often affected by the blocking or stacking
action of sickled cells are found in the lungs, liver , bone,
muscles, brain, spleen, penis, eyes, and kidneys.
The immune system of a person with sickled cells dramatically
weakens. People with sickle cells are highly susceptible to
infections from certain forms of bacteria. Some of the most
common infections are from flu viruses , pneumonia, and
salmonella (a type of bacteria).
Severe pain is the most common of sickle cell disease
emergencies (acute sickle cell crises). A person may not know
what brought on the pain, but one or more of the following
situations may have contributed to the start of the painful
sickle crisis:

Dehydration
Infection
Fever
Hypoxia (decrease in oxygen to body tissue)
Bleeding
Cold exposure
Drug and alcohol use
Pregnancy and stress
Four patterns of an acute sickle cell crisis are now
recognizable. They are based on the part of the body where
the crisis occurs.
Bone crisis: An acute or sudden pain in a bone can occur,
usually in an arm or leg. The area may be tender. Common
bones involved include the large bones in the arm or leg: the
humerus, tibia, and femur. The same bone may be affected
repeatedly in future episodes of bone crisis.
Acute chest syndrome: Sudden acute chest pain with coughing
up of blood can occur. Low-grade fevers can be present. The
person is usually short of breath. If a cough is present, it often
is nonproductive. Acute chest syndrome is common in a
young person with sickle cell disease. Chronic (long-term)
sickle cell lung disease develops with time because the acute
and subacute lung crisis leads to scarred lungs and other
problems.
Abdominal crisis: The pain associated with the abdominal
crisis of sickle cell disease is constant and sudden. It
becomes unrelenting. The pain may or may not be localized to
any one area of the abdomen. Nausea , vomiting , and diarrhea
may or may not occur.
Joint crisis: Acute and painful joint crisis may develop without
a significant traumatic history. Its focus is either in a single
joint or in multiple joints. Often the connecting bony parts of
the joint are painful. Range of motion is often restricted
because of the pain. Avascular necrosis of the hips can occur,
causing permanent damage.
Many other organ systems are often injured or impaired.
Central nervous system : Two-thirds of all strokes in people
with sickle cell disease occur in children, at an average age
of 8 years. About 10% of people with sickle cell disease have
strokes or other brain bleeding when younger than 8-10 years.
As the population ages, the incidence of these events also
increases. Repeat strokes occur in two-thirds of all survivors
within 3 years of the first stroke. Blood clots affect the large
vessels in the brain. Bleeding may occur in the small vessels
damaged by sickle cell disease.
Eyes: The effect of sickle cell disease on the eyes comes from
the increased viscosity, or "sludging," of blood and the
narrowness of the eye's blood vessels. Retinopathy (disease
of the retina in the eye) is common and causes problems with
vision. Retinal detachment is frequent. Hyphemas, bleeding in
the eye, occur at the same rate as the general population, but
complications are more common because of the increased
sickling effect that the waterlike fluid in the eye promotes.
Kidneys: Some amount of kidney damage occurs in nearly
every person with sickle cell disease.
Genitals: Priapism (a constant erection of the penis) is
common. It affects about 40% of all men with sickle cell
disease. Severe episodes are a frequent cause of impotency.
Infections: People with sickle cell disease have weakened
immune systems and are at increased risk for developing
infection, especially in the lungs, kidneys, bones, and central
nervous system.
Repeated crises damage the spleen, which over time, causes
it to stop functioning.
Blood problems: People with sickle cell disease can develop
anemia-a reduction in the number of red blood cells.
Symptoms of anemia are shortness of breath (oxygen is not
getting to tissues), lightheadedness, and fatigue .
Heart attacks can occur
The liver can also be affected by severe sickle cell crisis.

When to Seek Medical Care
If certain conditions develop in a person with sickle cell
disease, the person must contact a physician. If the
physician is not quickly available or cannot see the person
right away, the person with sickle cell disease may choose to
go to a hospital's emergency department. Contact the
physician in the following cases:
Many people with sickle-cell disease have pain with enough
frequency that they need to take pain medications at home. If
the pain is unrelieved by the medication, or the pain is
significantly different from previous episodes, contact the
health care provider.
If experiencing nausea, vomiting, and diarrhea; losing a lot of
fluid; and having inability to drink and keep it down, the
person with sickle cell disease is in danger of becoming
dehydrated. This is a serious concern with sickle cell disease.
The physician or the hospital may provide IV fluids to replace
the lost fluids.
It is important to control infection. If it appears that a person
with sickle cell disease is getting an infection, even if using
antibiotics to prevent infection, contact the physician
immediately.
A sickle cell crisis can often be managed efficiently and
quickly in a hospital's emergency department with fluids and
pain medicines. A person with sickle cell disease should not
delay going to the hospital. Delay can only make the condition
worse and might require hospitalization for treatment.
Go to a hospital's emergency department if these conditions
develop:
Uncontrollable pain even with the use of narcotics
Continued loss of fluid leading to dehydration (if vomiting)
Uncontrollable fever
Chest pain or shortness of breath
Severe abdominal pain