Sickle Cell Anaemia with Crisis

When sickle-shaped blood cells block vessels in the body, they trigger painful episodes known as sickle cell crises. These sudden events are a common complication that people with sickle cell disease face throughout their lives.

Table of contents

• What is a sickle cell crisis?
• Types of sickle cell crises
• Symptoms of a sickle cell crisis
• What causes a sickle cell crisis?
• Possible complications
• How is a crisis diagnosed?
• Treatment options
• Preventing a crisis
• Living with the condition

What is a sickle cell crisis?

A sickle cell crisis is a painful episode that can occur in people who have sickle cell disease. It happens when sickle-shaped red blood cells get stuck in a blood vessel and slow or stop blood flow^[1]. Red blood cells normally carry oxygen throughout the body, but during a crisis, these crescent-shaped cells block the flow of oxygen-rich blood to tissues and organs^[1].

The main feature of sickle cell disease is this acute painful crisis, which often requires hospital care^[3]. While some people can treat a crisis at home, severe cases may require a hospital stay for several days^[1].

Sickle cell disease affects about 1 in 500 African American children and 1 in 36,000 Hispanic American children^[3]. The disease is particularly common in people with an African or Caribbean family background^[7].

Types of sickle cell crises

There are four main types of sickle cell crises, each affecting the body differently^[1]:

• Vaso-occlusive crisis: This is the most common type. It happens when sickled cells block small blood vessels called capillaries, reducing blood flow to tissues and organs^[1]. Most patients with sickle cell disease experience this type by the age of 6 years^[3].
• Aplastic crisis: This occurs when the bone marrow stops producing red blood cells^[1].
• Hyperhemolytic crisis: This happens when hemoglobin (the protein that carries oxygen in red blood cells) levels drop quickly. It can occur after a blood transfusion, which is a common treatment for sickle cell disease^[1].
• Splenic sequestration: This occurs when sickled cells get stuck in the spleen and cause painful swelling^[1].

Symptoms of a sickle cell crisis

The symptoms of a sickle cell crisis can vary depending on which areas of the body are affected^[1]. Common symptoms include:

• Pain (which can be dull, intense, throbbing or stabbing)^[1]
• Dizziness^[1]
• Fatigue^[1]
• Headaches^[1]
• Jaundice (yellowing of the skin or eyes)^[1]
• Shortness of breath^[1]
• Weakness^[1]

Pain is the most common sign and might appear suddenly^[6]. It can last anywhere from a few hours to several days or even weeks^[1][2]. Pain can occur anywhere in the body and affect one or more areas at the same time^[1].

The most frequently affected areas are^[1][3]:

• Arms or hands
• Chest
• Legs or feet
• Lower back
• Stomach

In young children, a vaso-occlusive crisis can cause severe pain and swelling of both hands and feet, a condition called dactylitis^[3].

What causes a sickle cell crisis?

A sickle cell crisis happens when sickle-shaped red blood cells build up and block a blood vessel^[1]. The blockage creates regional low oxygen levels and acidosis (when the body becomes too acidic), which creates a pattern of further sickling, tissue injury and pain^[17].

However, experts don’t always know what triggers a crisis^[1]. In most patients, a pain crisis happens without an obvious cause^[6]. Possible triggers include^[1][8]:

• Dehydration (not having enough fluids)
• High altitudes (such as mountain climbing)
• Infections
• Pregnancy
• Smoking or vaping
• Strenuous physical activity
• Stress
• Sudden, extreme temperature changes (such as going from a warm house into cold winter weather)
• Vitamin deficiencies

The frequency, severity, location and duration of pain crises can vary considerably between individuals, even among those with the same disease type^[17]. Some people have only a few pain crises a year, while others have many^[2]. About 5.2 percent of patients with sickle cell disease have three to 10 episodes of severe pain every year^[17].

Possible complications

When blood vessels in tissues or organs become blocked during a crisis, it can lead to serious complications^[1]. The severity depends on the location of the blocked blood vessel^[1].

Possible complications include^[1][3]:

• Acute chest syndrome (when sickled cells block blood vessels in the lungs)
• Blood clots
• Chronic pain
• Enlarged spleen and other spleen conditions
• Leg ulcers
• Liver disease
• Lung conditions
• Necrosis (bone or tissue death due to lack of blood flow)
• Painful erections (priapism)
• Stroke
• Pneumonia
• Meningitis
• Sepsis
• Osteomyelitis (bone infection)

More than 50% of people with sickle cell disease have acute chest syndrome because of the small vessels in the lungs^[6]. This can lead to low oxygen levels in the short term as well as long-term lung complications^[6].

How is a crisis diagnosed?

If you have sickle cell disease, you likely already visit your healthcare provider every six to 12 months for routine blood tests^[1]. However, if you’re experiencing a sickle cell crisis, you’ll need a full laboratory assessment^[1].

Tests may include^[1]:

• Blood type test (in case you need a blood transfusion)
• CBC (complete blood count)
• CMP (comprehensive metabolic panel)
• Liver function tests
• Reticulocyte count (a measure of young red blood cells)

In addition, your healthcare provider will perform a full physical examination and may order imaging tests, such as^[1]:

• Doppler ultrasound
• MRI (magnetic resonance imaging)
• Ultrasound

The evaluation is primarily performed to determine the severity of the crisis^[3]. When a crisis lasts longer than seven days, it is important to search for other causes of bone pain, such as bone infection, avascular necrosis (death of bone tissue due to lack of blood supply), and compression deformities^[17].

Treatment options

Treatment focuses on managing pain and preventing complications^[3]. The approach depends on the severity of symptoms^[1].

Home treatment for mild cases

For mild pain, you can often manage the crisis at home with^[1][8]:

• Over-the-counter pain relievers such as acetaminophen (Tylenol) or ibuprofen (Advil, Motrin)
• Drinking plenty of fluids
• Using heated pads to soothe the pain
• Rest

It’s important to talk to your doctor about what medications are safe for you. For example, if you have a kidney problem, acetaminophen might be the better choice^[6].

Hospital treatment for severe cases

If symptoms become severe, you may need to stay in the hospital for a few days^[1]. Hospital treatment may include^[1][12]:

• Stronger pain medicines given through a vein (intravenous), such as morphine
• Intravenous fluids to treat dehydration
• Antibiotics if there is an infection
• Blood transfusions if symptoms continue or get worse
• Oxygen if blood oxygen levels are low

United States and United Kingdom guidelines emphasize the need for prompt pain relief, ideally within 30 minutes of arrival at the emergency department^[12]. Early achievement of maximum pain relief has been shown to shorten hospital stays in children with sickle cell disease^[12].

Medicines to prevent crises

Several medicines can help prevent crises and reduce complications^[6][11]:

• Hydroxyurea (Droxia, Hydrea, Siklos): This medicine reduces the frequency of pain crises and might reduce the need for blood transfusions and hospital stays^[11].
• L-glutamine oral powder (Endari): This medicine helps prevent crises and hospitalizations^[6].
• Crizanlizumab (Adakveo): This medicine helps stop blood cells from sticking together and blocking blood vessels^[6].

Note: Voxelotor (Oxbryta), which was used to prevent abnormal red blood cells, was withdrawn from the market in September 2024 due to safety concerns^[6][14].

Other treatments

People with sickle cell disease need treatment throughout their lives^[13]. Additional treatments may include^[7][13]:

• Daily antibiotics (usually penicillin) and regular vaccinations to reduce the risk of infections
• Folic acid supplements to help stimulate red blood cell production
• Regular blood transfusions if symptoms continue or worsen
• Emergency blood transfusions if severe anemia (shortage of red blood cells) develops

The only cure for sickle cell disease is a stem cell or bone marrow transplant, but these are not done very often because of the significant risks involved^[7][13]. In December 2023, two new gene therapies were approved that offer transformative treatment options for some patients^[14].

Preventing a crisis

While you can’t always prevent a sickle cell crisis, there are steps you can take to reduce your risk^[8][19]:

Stay hydrated

Drink plenty of fluids, especially 8 to 10 glasses of water every day^[8][18]. Drink even more during hot weather, before and after exercise, or when you have a fever or infection^[8].

Maintain a comfortable temperature

Dress warmly in cold weather and try to avoid getting too cold or too hot^[8][19]. Avoid sudden temperature changes, such as swimming in cold water^[8].

Avoid high altitudes

The lack of oxygen at high altitudes may trigger a crisis^[8][19]. Commercial air travel should be safe because planes are pressurized to maintain steady oxygen levels^[19].

Exercise with care

Physical activity is important for staying healthy, but avoid very strenuous exercise that makes you seriously out of breath^[19]. Rest when you feel tired and drink plenty of fluids during activity^[8].

Prevent infections

Common illnesses can quickly become dangerous if you have sickle cell disease^[21]. Take these steps^[18][19]:

• Wash your hands often with soap and water
• Get all recommended vaccines, including the annual flu shot and pneumococcal and meningococcal vaccines
• Take daily antibiotics if prescribed by your doctor
• Prepare food safely to prevent food poisoning

Avoid harmful substances

Stay away from^[19][21]:

• Alcohol (it can cause dehydration)
• Smoking and vaping (these can trigger acute chest syndrome and other lung problems)

Manage stress

Stress can trigger a sickle cell crisis^[19]. It may help to learn relaxation techniques such as breathing exercises^[19].

Get regular medical care

See your healthcare provider regularly for checkups and blood tests^[18]. Most people with sickle cell disease should see their provider every 3 to 12 months, depending on their age and type of disease^[18].

Living with the condition

People with sickle cell disease can live full lives and enjoy most of the activities that other people do^[18][23]. Making smart choices is important in keeping the condition from flaring into a crisis^[21].

Create a pain management plan

Work with your doctor to create a plan for handling pain crises^[8]. This plan should include^[8]:

• Types of medicines you can take at home
• Other actions to relieve pain (such as using heating pads or physical therapy)
• When to call your doctor or go to the hospital

Identify your pain triggers

Every time you experience sudden pain, try to figure out what may have caused it^[21]. Although it may not be obvious at first, keeping a long-running list over time could help you find a pattern^[21].

Take care of your overall health

Maintain healthy habits^[21][23]:

• Eat plenty of fruits, vegetables, whole grains and protein
• Get enough sleep
• Stay active with moderate exercise (about 2½ hours per week)
• Take your prescribed medicines as directed

When to seek immediate medical care

Contact your doctor or healthcare team straight away if you develop any of these symptoms^[19]:

• High temperature over 38°C (or any increased temperature in a child)
• Severe pain that’s not responding to home treatment
• Severe vomiting or diarrhea
• Severe headache, dizziness or stiff neck
• Breathing difficulties
• Very pale skin or lips
• Sudden swelling in the stomach
• Painful erection lasting more than 2 hours
• Confusion, drowsiness or slurred speech
• Fits (seizures)
• Weakness on one or both sides of the body
• Changes in vision or sudden vision loss

If you cannot reach your doctor, go to your nearest emergency department. If you’re not well enough to travel yourself, dial emergency services for an ambulance^[19].

Make sure medical staff know you have sickle cell disease. Many emergency departments have a standardized treatment plan in place for sickle cell crises^[12]. It’s helpful to bring your pain management plan information with you to the hospital^[1].

Find support

Living with sickle cell disease can be challenging. Consider finding a patient support group or community-based organization that can provide information, assistance and support^[23]. Your healthcare team, which may include a hematologist and other specialists, can also provide ongoing support and guidance^[12].