Sickle cell disease is a condition many healthcare professionals outside specialist centres encounter infrequently, yet for affected families it is a constant presence: the threat of sudden severe pain, the risk of infection, the hospital admissions, and the long-term management that begins in the neonatal period and continues through life.
The newborn bloodspot screening programme identifies affected babies in the first days of life, and early intervention – penicillin prophylaxis, vaccination, parental education about fever management – has dramatically reduced early mortality in the UK. Understanding what sickle cell disease is, what the warning signs are, and when to seek urgent help is essential for any family affected by the condition.
Healthbooq (healthbooq.com) covers genetic conditions and haematological health in children.
What Sickle Cell Disease Is
Sickle cell disease results from a mutation in the beta-globin gene that causes haemoglobin S (HbS) to be produced instead of normal haemoglobin A. When deoxygenated (when oxygen is released to tissues), HbS polymerises and distorts red blood cells into a sickle or crescent shape. These sickle cells are fragile (causing haemolytic anaemia), sticky (causing blood vessel obstruction), and rigid (unable to deform to pass through narrow capillaries).
The most common forms of SCD are: HbSS (inheriting two copies of the HbS mutation – the most severe form, called sickle cell anaemia); HbSC (inheriting HbS from one parent and HbC from the other – usually milder than HbSS); and HbS/beta-thalassaemia (inheriting HbS from one parent and a beta-thalassaemia mutation from the other – severity depends on the thalassaemia mutation).
SCD inheritance follows autosomal recessive pattern. Sickle cell trait (one copy of HbS) confers no disease in normal circumstances but the carrier state should be known for family planning.
How SCD Is Identified in Newborns
The NHS Newborn Bloodspot Screening Programme (the heel prick test at 5 days of age) tests for SCD alongside other conditions. Results are returned to the family's GP, midwife, or health visitor. Families who receive a positive result are referred immediately to a specialist haematology or sickle cell team.
If a family is known to have sickle cell trait in both parents, prenatal diagnosis (chorionic villus sampling or amniocentesis) is offered.
Sickle Cell Crisis
A vaso-occlusive pain crisis (VOC) is the most common complication of SCD. Sickle cells obstruct small blood vessels, causing ischaemia and intense pain typically in bones, chest, abdomen, or joints. Pain crises can be triggered by infection, cold, dehydration, stress, or exertion, but often occur without identifiable cause.
Management of a mild-moderate crisis: oral analgesia (paracetamol, NSAIDs, opioids if needed), oral fluids, warmth, and regular reassessment. Severe or uncontrolled pain requires hospital admission for IV fluids and IV opioid analgesia. NICE guidance (NG143) recommends offering pain relief within 30 minutes of arriving at hospital and IV morphine within 60 minutes for severe crisis.
Acute chest syndrome is a life-threatening complication: fever, chest pain, respiratory distress, and a new pulmonary infiltrate on chest X-ray. It requires urgent hospital management including blood transfusion, broad-spectrum antibiotics, and sometimes exchange transfusion.
Splenic sequestration (predominantly in young children before the spleen autoinfarcts): sudden dramatic spleen enlargement trapping large volumes of blood, causing hypovolaemia, severe anaemia, and cardiovascular collapse. Parents of young children with SCD are taught to palpate the spleen daily and to seek immediate medical attention if it becomes enlarged.
Stroke occurs in approximately 11% of children with HbSS by age 20. Transcranial Doppler ultrasound (TCD) screening identifies children at high risk (elevated cerebral artery velocities) and regular blood transfusions reduce stroke risk by 90%.
Penicillin Prophylaxis
Children with SCD have functional asplenia (the spleen autoinfarcts progressively over the first years of life) and are at very high risk of overwhelming infection from encapsulated bacteria – pneumococcus, meningococcus, and Haemophilus influenzae. All children with SCD should receive:
Oral penicillin V from the time of diagnosis (ideally before 3 months) until at least age 5, and lifelong for children with HbSS who have had a serious pneumococcal infection.
Enhanced vaccinations: all standard schedule vaccines plus additional pneumococcal vaccines (PCV13 and PPV23), meningococcal ACWY and B vaccines, and annual influenza vaccine.
Hydroxyurea
Hydroxyurea (also called hydroxycarbamide) increases fetal haemoglobin (HbF) production, which inhibits HbS polymerisation and reduces sickling. Trials including the BABY HUG trial (Wang et al., 2011, Lancet) established efficacy and safety in children as young as 9 months. NICE recommends hydroxyurea for all children with HbSS or HbS/beta0-thalassaemia with significant disease.
Fever Management
Any fever above 38 degrees in a child with SCD requires same-day hospital assessment and blood cultures. The risk of rapidly progressing bacteraemia is high enough that empirical IV antibiotics are started without waiting for culture results.
Key Takeaways
Sickle cell disease (SCD) is the most common serious genetic condition in the UK, affecting around 15,000 people, with approximately 400 babies born with the condition each year identified through the NHS newborn bloodspot screening programme. SCD causes haemolytic anaemia, recurrent vaso-occlusive pain crises, increased susceptibility to infection (particularly with encapsulated bacteria), and organ damage over time. All children with SCD should receive penicillin prophylaxis from diagnosis until at least age 5, and pneumococcal, meningococcal, and Haemophilus influenzae type b vaccines. Hydroxyurea (hydroxycarbamide) increases fetal haemoglobin and significantly reduces pain crisis frequency, acute chest syndrome, and transfusion requirements. Potentially curative treatments include haematopoietic stem cell transplantation and, increasingly, gene therapy.
