Sickle Cell Disease Flashcards
Definition
What is sickle cell disease?
Sickle cell disease is an inherited blood disorder marked by defective hemoglobin. It inhibits the ability of hemoglobin in red blood cells to carry oxygen. Sickle cells tend to stick together, blocking small blood vessels causing painful and damaging complications.
Main results
Description
A group of disorders that cause red blood cells to become misshapen and break down.
With sickle cell disease, an inherited group of disorders, red blood cells contort into a sickle shape. The cells die early, leaving a shortage of healthy red blood cells (sickle cell anaemia) and can block blood flow causing pain (sickle cell crisis).
Overview
Red blood cells and sickle cells
Sickle cell anemia Open pop-up dialog box
Sickle cell anemia is one of a group of inherited disorders known as sickle cell disease. It affects the shape of red blood cells, which carry oxygen to all parts of the body.
Red blood cells are usually round and flexible, so they move easily through blood vessels. In sickle cell anemia, some red blood cells are shaped like sickles or crescent moons. These sickle cells also become rigid and sticky, which can slow or block blood flow.
Symptoms
Symptoms
Symptoms
y Joint and bone pain, especially during cold wet seasons
y Easy fatiguability
y Pallor
y Jaundice
y Difficulty in breathing with or without chest pain
y Chronic leg ulcer
y Abdominal pain, especially in the splenic area
y Spontaneous sustained erection without sexual arousal in male
patients (See section on ‘Priapism’)
Signs
y Jaundice
y Pallor
y Hepatomegaly
y Splenomegaly (may be absent in older patients)
y Old or recent scarification marks by traditional healers, particularly
over the abdominal wall and joints y Venous ulcers
y Bossing
y Dactylitis (hand and foot syndrome)
y Gnathopathy
y Growth delay or tall, lanky stature (‘marfanoid’ habitus)
Signs and symptoms of sickle cell anemia usually appear around 6 months of age.
They vary from person to person and may change over time. Signs and symptoms can include:
Anemia. Sickle cells break apart easily and die. Red blood cells usually live for about 120 days before they need to be replaced. But sickle cells typically die in 10 to 20 days, leaving a shortage of red blood cells (anemia). Without enough red blood cells, the body can’t get enough oxygen and this causes fatigue.
Episodes of pain. Periodic episodes of extreme pain, called pain crises, are a major symptom of sickle cell anemia. Pain develops when sickle-shaped red blood cells block blood flow through tiny blood vessels to your chest, abdomen and joints.
The pain varies in intensity and can last for a few hours to a few days. Some people have only a few pain crises a year. Others have a dozen or more a year. A severe pain crisis requires a hospital stay.
Some adolescents and adults with sickle cell anemia also have chronic pain, which can result from bone and joint damage, ulcers, and other causes.
Swelling of hands and feet. The swelling is caused by sickle-shaped red blood cells blocking blood circulation in the hands and feet.
Frequent infections. Sickle cells can damage the spleen, increasing vulnerability to infections. Infants and children with sickle cell anemia commonly receive vaccinations and antibiotics to prevent potentially life-threatening infections, such as pneumonia.
Delayed growth or puberty. Red blood cells provide the body with the oxygen and nutrients needed for growth. A shortage of healthy red blood cells can slow growth in infants and children and delay puberty in teenagers.
Vision problems. Tiny blood vessels that supply the eyes can become plugged with sickle cells. This can damage the retina — the portion of the eye that processes visual images — and lead to vision problems.
When to see a doctor
See your health care provider right away if you or your child has symptoms of sickle cell anemia. Because children with sickle cell anemia are prone to infections, which often start with a fever and can be life-threatening, seek prompt medical attention for a fever greater than 101.5 F (38.5 C).
Seek emergency care for symptoms of stroke, which include:
One-sided paralysis or weakness in the face, arms or legs
Confusion
Difficulty walking or talking
Sudden vision changes
Unexplained numbness
Severe 🤕
Shortness of breath and fatigue are common symptoms of this condition, which can be fatal. Organ damage. Sickle cells that block blood flow to organs deprive the affected organs of blood and oxygen.
Causes
Causes
y Inheritance of two abnormal haemoglobin genes from both parents, at least one of which is an S.
y Crises are typically precipitated by:
y cold weather
y dehydration
y infection
y physical exertion
y mental stress
Sickle cell anemia is caused by a change in the gene that tells the body to make the iron-rich compound in red blood cells called hemoglobin. Hemoglobin enables red blood cells to carry oxygen from the lungs throughout the body.
The hemoglobin associated with sickle cell anemia causes red blood cells to become rigid, sticky and misshapen.
For a child to be affected, both mother and father must carry one copy of the sickle cell gene — also known as sickle cell trait — and pass both copies of the altered form to the child.
If only one parent passes the sickle cell gene to the child, that child will have the sickle cell trait. With one typical hemoglobin gene and one altered form of the gene, people with the sickle cell trait make both typical hemoglobin and sickle cell hemoglobin.
Their blood might contain some sickle cells, but they generally don’t have symptoms.
They’re carriers of the disease, however, which means they can pass the gene to their children.
What causes the sickle cell disease?
To be born with sickle cell disease, a child has to inherit a copy of the sickle cell gene from both their parents. This usually happens when both parents are “carriers” of the sickle cell gene, also known as having the sickle cell trait.
Risk Factors
Risk factors
For a baby to be born with sickle cell anemia, both parents must carry a sickle cell gene. In the United States, sickle cell anemia most commonly affects people of African, Mediterranean and Middle Eastern descent.
Complications
Complications
Sickle cell anemia can lead to a host of complications, including:
— Stroke. Sickle cells can block blood flow to an area of the brain.
Signs of stroke include
- seizures,
- weakness or numbness of the arms and legs,
- sudden speech difficulties, and
- loss of consciousness.
If your child has any of these signs and symptoms, seek medical treatment immediately.
A stroke can be fatal.
— Acute chest syndrome. A lung infection or sickle cells blocking blood vessels in the lungs can cause this life-threatening complication, resulting in
- chest pain,
- fever and
- difficulty breathing.
It might require emergency medical treatment.
— Pulmonary hypertension. People with sickle cell anemia can develop high blood pressure in their lungs.
This complication usually affects adults.
- Shortness of breath and
- fatigue are common symptoms of this condition, which can be fatal.
— Organ damage. Sickle cells that block blood flow to organs deprive the affected organs of blood and oxygen. In sickle cell anemia, blood is also chronically low in oxygen. This lack of oxygen-rich blood can damage nerves and organs, including kidneys, liver and spleen, and can be fatal.
— Splenic sequestration. A large number of sickle cells can get trapped in the spleen, causing it to enlarge and possibly causing belly pain on the left side of the body.
This can be life-threatening.
Parents of children with sickle cell anemia should learn to regularly feel their child’s spleen for enlargement.
— Blindness. Sickle cells can block tiny blood vessels that supply the eyes. Over time, this can lead to blindness.
— Leg ulcers. Sickle cell anemia can cause painful open sores on the legs.
—Gallstones. The breakdown of red blood cells produces a substance called bilirubin. A high level of bilirubin in the body can lead to gallstones.
— Priapism. In this condition, men with sickle cell anemia can have painful, long-lasting erections. Sickle cells can block the blood vessels in the penis, which can lead to impotence over time.
— Deep vein thrombosis. Sickling of red cells can cause blood clots, increasing the risk of a
- clot lodging in a deep vein (deep vein thrombosis) or a
- lung (pulmonary embolism).
Either can cause serious illness or even death.
— Pregnancy complications. Sickle cell anemia can increase the risk of
- high blood pressure and
- blood clots during pregnancy.
It can also increase the risk of
- miscarriage,
- premature birth and
- having low birth weight babies.
Note Prevention
Prevention
If you carry the sickle cell trait, seeing a genetic counselor before trying to conceive can help you understand your risk of having a child with sickle cell anemia. A genetic counselor can also explain possible treatments, preventive measures and reproductive options.
Sickle cell Crisis
Four major types of crises are recognised in sickle cell anaemia:
— aplastic,
— acute sequestration,
— hyper-haemolytic, and
— vaso-occlusive crises.
Vaso occlusive crisis
A vaso-occlusive crisis most commonly involves the back, legs, knees, arms, chest and abdomen. The pain generally affects two or more sites. Bone pain tends to be bilateral and symmetric. Recurrent crises in an individual patient usually have the same distribution
Aplastic Crisis
Aplastic crisis is a condition in which the bone marrow of someone with sickle cell disease suddenly stops producing red blood cells. This causes sudden and severe anemia. The crisis is usually caused by an infection with parvovirus. This is the virus that causes fifth disease in children.
Symptoms may develop slowly or suddenly. Fatigue, frequent infections, rapid heart rate and bleeding may occur.
People may experience:
Whole body: fatigue, dizziness, or fever
Skin: rash of small purplish spots or red spots
Also common: bleeding, bruise, fast heart rate, frequent infections, nosebleed, pale skin, or shortness of breath
Acute Splenic sequestration crisis ASSC
Acute splenic sequestration crisis (ASSC) is a life-threatening complication associated with sickle cell anemia (SCA) that consists of an acute fall in hemoglobin produced by red blood cell (RBC) sickling within the spleen. It is also one of the leading causes of death in children with SCA.
increasing pain on the left side
severe belly pain or swelling
a spleen that feels bigger or firmer, or is tender to touch
fatigue (extreme tiredness)
dizziness
a fast heartbeat
pale skin
a headache
Hyper haemolytic Crisis
Introduction: Hyperhemolytic crisis is a rare and dangerous complication of sickle cell disease where the hemoglobin level drops rapidly. This can quickly lead to organ failure and death. In the literature, most cases of hyperhemolysis in sickle cell patients followed a red cell transfusion.
Hyperhemolytic crisis presents with a myriad of symptoms that can include fever and pain, evidence of hemolysis, development of severe anemia after transfusion, and a fall in absolute reticulocyte count that is followed by a rise in hemoglobin and reticulocyte count.
This is an inherited disease characterized by the possession of two abnormal haemoglobins, at least one of which is haemoglobin S. There are various types, including HBSS, HBSC and HBS βthalassaemia. The possession of one normal haemoglobin (haemoglobin A) together with one abnormal haemoglobin (e.g. AS or AC) constitute a haemoglobinopathy trait and not sickle cell disease.
The use of the word ‹sickler› to describe patients with sickle cell disease must be avoided. Sickle cell disease patients may present either inthesteadystate,incrisesorwithcomplications. Thecrisisiscommonly vaso-occlusive bone pain crisis. Other types of crises include acute chest syndrome, hyper-haemolytic crisis, aplastic crisis and sequestration crises. In vaso-occlusive crises there is occlusion of small vessels by sickled cells causing infarction and pain; in Acute Chest Syndrome (ACS), the patient presents with sudden onset of cough, difficulty in breathing and fever; in aplastic crises, infection with parvovirus causes sudden severe anaemia with a low reticulocyte count; in sequestration crises the spleen and liver enlarge rapidly due to trapping of red blood cells.
Patients with sickle cell disease should be encouraged to have periodic check-ups at a sickle cell clinic.
Investigations
Investigations
y FBC
y Blood film comment
y Reticulocyte count
y Sickling test
y Haemoglobin electrophoresis
y Urine examination
y Chest X-ray in case of ACS
y Blood and urine C/S when infection suspected
y G6PD assay
Treatment
STG page 70
Patients with suspected acute chest syndrome should have an urgent chest X-ray, blood and urine C/S, blood for grouping and cross-matching
Note 4-2
If the pain is not controlled by the measures above within 12 hours, consult a specialist. Pethidine is no longer the recommended drug of choice. Morphine may be used but specialist consultation is required.
Caution: long term NSAIDS (for more than two weeks) e.g. Diclofenac and Ibu- profen may cause renal impairment, and gastritis
