Sickle Cell Disease
Inherited haemoglobinopathy causing painful vaso-occlusive crises, anaemia and chronic organ damage.
Overview
Sickle cell disease (most commonly HbSS) is the UK's most common serious inherited disorder. Polymerised sickle haemoglobin distorts red cells, blocking microcirculation and shortening red-cell survival. Modern care with hydroxycarbamide, transfusion programmes and emerging gene therapy substantially improves outcomes.
Symptoms
- • Recurrent vaso-occlusive pain crises (bones, abdomen, chest)
- • Fatigue and pallor from chronic haemolytic anaemia
- • Jaundice, gallstones
- • Recurrent infections (especially encapsulated organisms)
- • Stroke, priapism, leg ulcers, chronic kidney disease
Risk factors
- • Sub-Saharan African, Caribbean, Mediterranean, Middle Eastern, Indian ancestry
- • Both parents being carriers (sickle cell trait)
- • Dehydration, hypoxia, cold, infection (precipitate crises)
Causes
- • Homozygous HbS (HbSS) — most severe
- • Compound heterozygous: HbSC, HbS/β-thalassaemia
- • Autosomal recessive inheritance
🚨 Red flags — seek urgent care
- • Acute chest syndrome: chest pain, fever, hypoxia, new infiltrate — emergency
- • Stroke or TIA — even in children
- • Splenic sequestration: sudden splenomegaly + falling Hb
- • Priapism >4 hours — urological emergency
- • Febrile patient — risk of overwhelming sepsis
When to seek care
- • Severe pain not controlled by usual regimen
- • Fever ≥38°C — same-day assessment
- • New breathlessness, chest pain or neurological symptoms
Diagnosis
- • Newborn heel-prick screening
- • Haemoglobin electrophoresis or HPLC confirms type
- • FBC: normocytic anaemia, reticulocytosis, sickle cells on film
- • Annual transcranial Doppler in children to identify stroke risk
- • Baseline pulmonary, renal, hepatic, retinal assessment
Treatment
- • Hydroxycarbamide — first-line disease-modifying therapy from infancy
- • Penicillin prophylaxis to age 5, pneumococcal/meningococcal/Hib vaccination
- • Folic acid 5 mg daily
- • Crisis management: warmth, hydration, opioid analgesia (morphine), oxygen if hypoxic
- • Acute chest syndrome: oxygen, broad-spectrum antibiotics, exchange transfusion
- • Regular transfusion or exchange transfusion for stroke prevention
- • Stem-cell transplant for severe disease in selected patients; gene therapy (exa-cel) emerging
Prevention
- • Prenatal carrier screening and counselling
- • Avoid dehydration, hypoxia, extreme cold
- • Vaccination and prompt treatment of infections
- • Annual specialist review and stroke screening in children
Complications
- • Stroke (overt and silent), cognitive impairment
- • Acute chest syndrome (leading cause of death in adults)
- • Avascular necrosis (hips, shoulders)
- • Chronic kidney disease, pulmonary hypertension
- • Iron overload from transfusions; alloimmunisation
Prognosis
Median survival has improved from childhood to over 50 years in the UK with comprehensive care; transplant and gene therapy can be curative.
Education & self-care
Daily medication, vaccinations, early treatment of infection, and prompt care for chest pain or stroke symptoms are life-saving. Comprehensive specialist care is essential.
Frequently asked questions
Will my baby have sickle cell?
Only if both parents carry the sickle gene — 1 in 4 chance per pregnancy.
Is sickle cell curable?
Stem-cell transplant from a matched sibling and new gene therapies can cure selected patients.
Can I exercise?
Yes — moderate, well-hydrated exercise is encouraged; avoid extremes that trigger crises.