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