Hematology

Sickle Cell Disease song

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Sickle Cell Disease

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Key points in this song10

Sickle cell disease is caused by a point mutation in the beta-globin gene (Glu→Val at position 6), producing HbS that polymerizes under low oxygen, acidosis, or dehydration, causing RBC sickling.
HbS heterozygotes (sickle cell trait) are generally asymptomatic but have relative protection against Plasmodium falciparum malaria due to altered RBC environment.
Vaso-occlusive (pain) crisis is the most common complication, triggered by infection, dehydration, hypoxia, or cold; treated with IV fluids, oxygen, and analgesics including opioids.
Splenic sequestration crisis causes sudden splenomegaly and circulatory collapse in young children; functional asplenia develops by age 5 due to autoinfarction, increasing risk for encapsulated organisms (Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis).
Aplastic crisis is most commonly caused by Parvovirus B19, which halts erythropoiesis, presenting with sudden drop in hemoglobin and absent reticulocytes.
Acute chest syndrome presents with fever, pleuritic chest pain, new pulmonary infiltrate, and hypoxia; it is the leading cause of death in sickle cell disease and is treated with exchange transfusion, antibiotics, and incentive spirometry.
Stroke occurs in up to 10% of children with sickle cell disease; transcranial Doppler screening is recommended starting at age 2, and chronic transfusion therapy is used for primary stroke prevention in high-risk patients.
Hydroxyurea increases HbF production, reducing sickling frequency; it decreases painful crises, acute chest syndrome episodes, and transfusion requirements, and is first-line disease-modifying therapy.
Avascular necrosis of the femoral head and Salmonella osteomyelitis (most common cause of osteomyelitis in sickle cell disease) are classic musculoskeletal complications.
Newborn screening uses hemoglobin electrophoresis; HbSS pattern shows predominant HbS with no HbA, distinguishing it from HbSC disease (HbS + HbC) and sickle cell trait (HbAS).