Signs and Symptoms
- Sickle cell disease usually begins in early childhood
- Severity of symptoms can vary from person to person
- Acute and chronic complications can occur, with high mortality rates
- Sickle cell crisis can manifest in various types, including vaso-occlusive crisis, aplastic crisis, splenic sequestration crisis, and haemolytic crisis
- Most episodes of sickle cell crises last between five and seven days
- Vaso-occlusive crisis is caused by sickle-shaped red blood cells obstructing capillaries and restricting blood flow, resulting in ischemia, pain, necrosis, and organ damage
- Splenic sequestration crisis is characterised by acute and painful enlargements of the spleen, caused by sickle-shaped red blood cells narrowing blood vessels and reducing spleen function
- Acute chest syndrome is defined by chest pain, fever, pulmonary infiltrate or abnormality, respiratory symptoms, or hypoxemia
- Aplastic crisis is an acute worsening of baseline anemia triggered by parvovirus B19

Complications
- Increased risk of severe bacterial infections due to loss of functioning spleen tissue
- Stroke can result from progressive narrowing of blood vessels
- Silent stroke causes damage to the brain
- Cholelithiasis and cholecystitis may result from excessive bilirubin production
- Avascular necrosis of the hip and other major joints may occur

Genetics
- Sickle cell disease is inherited in an autosomal recessive pattern
- Different geographic areas have different variants of the sickle cell gene mutation
- The gene defect is a single nucleotide mutation of the β-globin gene

Other Complications
- Decreased immune reactions due to hyposplenism
- Priapism and infarction of the penis
- Osteomyelitis is a common cause of bone infection
- Acute papillary necrosis in the kidneys
- Eye complications such as retinopathy and blindness can occur

Diagnosis and Management
- Diagnosis involves complete blood count, blood film, hemoglobin electrophoresis, and other tests
- Management includes regular exercise, hydration, calcium-rich diet, and L-glutamine use
- Penicillin is recommended for children with sickle cell disease
- Malaria prevention is important for individuals with sickle cell trait
- Treatment for vaso-occlusive crises involves pain management and fluid replacement
- Transcranial Doppler ultrasound and blood transfusions are used for stroke prevention
- Acute chest syndrome is managed similarly to vaso-occlusive crisis, with antibiotics and supportive care
- Hydroxyurea and bone marrow transplant are treatment options for sickle cell disease