Sickle cell disease (SCD) is a group of inherited blood disorders characterized by an abnormality in the oxygen-carrying protein hemoglobin, causing red blood cells to adopt a rigid, crescent shape under certain conditions. These misshapen cells are less flexible than normal disc-shaped cells and can block small blood vessels, which leads to a painful event known as a sickle cell crisis. These crises are the most common reason for emergency room visits and hospitalizations in children with SCD. Prevention is the primary goal of care, requiring medical treatments, careful daily management, and proactive monitoring to minimize the frequency and severity of complications.
Pharmacological and Prophylactic Treatments
The primary medical strategy for reducing the frequency of sickle cell crises involves disease-modifying therapies managed by a hematologist. Hydroxyurea is a foundational oral medication that protects red blood cells. It works primarily by increasing the production of fetal hemoglobin (HbF), which does not sickle, effectively diluting the abnormal hemoglobin S.
This increase in HbF delays the sickling process and improves the flexibility of red blood cells. Hydroxyurea also reduces white blood cells and platelets, components that contribute to blood vessel blockage. Adherence to the daily dose is important, and the dosage is adjusted based on routine blood counts.
Newer therapies target different parts of the disease process. L-Glutamine reduces oxidative stress on red blood cells to decrease their stickiness. Voxelotor binds directly to hemoglobin S, increasing its affinity for oxygen and making it more difficult for the cell to sickle.
Daily Penicillin is an important prophylactic treatment. Young children with SCD are at high risk for life-threatening bacterial infections, such as pneumococcal sepsis, because the disease often causes the spleen to lose its function early. Prophylaxis is typically started in infancy and continued daily until at least five years old to prevent these infections.
Managing Triggers and Daily Care
Avoiding common environmental and behavioral triggers is crucial for crisis prevention. Dehydration is one of the most common and easily avoided triggers, as a lack of fluid causes the blood to become thicker, promoting sickling. Children with SCD should maintain a consistent, high fluid intake based on their weight, and should always have water accessible.
Regulating body temperature is another important daily consideration, as exposure to extremes can initiate a crisis. Cold temperatures cause blood vessels to constrict, slowing blood flow and making it easier for sickled cells to get stuck. Excessive heat can lead to rapid dehydration through sweating, which also increases the risk of sickling.
Parents should ensure the child is dressed appropriately and avoid sudden temperature changes, such as moving quickly from a hot exterior into a cold, air-conditioned room. Swimming in cold water should be avoided, and children should be dried and warmed immediately after leaving the water.
Fatigue and emotional stress are also documented triggers that can precipitate a pain episode. Ensuring the child receives adequate, consistent sleep and helping them develop healthy coping mechanisms are helpful strategies for managing these behavioral triggers.
Infection Prevention Strategies
Infections pose a significant danger to children with SCD and are a major trigger for sickle cell crises. Children are vulnerable to encapsulated bacteria, such as Streptococcus pneumoniae and Neisseria meningitidis. Therefore, a comprehensive and augmented vaccination schedule is necessary.
Children must receive all routine childhood vaccinations on schedule, including the annual inactivated influenza vaccine starting at six months of age. Specific vaccines are given with an altered schedule to provide broader protection. This includes Pneumococcal Conjugate (PCV13) and Polysaccharide (PPSV23) vaccines.
Meningococcal vaccines (MenACWY and MenB) are also given at an earlier age and in more doses than the standard schedule to protect against severe meningitis. Maintaining stringent general hygiene, including consistent handwashing, helps to minimize exposure to infectious agents. During peak illness seasons, it is prudent to limit exposure to large crowds.
Routine Monitoring and Comprehensive Care
Proactive medical oversight is necessary to monitor disease progression and prevent severe complications. Regular check-ups with a pediatric hematologist are important for managing medication adherence, addressing side effects, and reviewing the child’s overall health status. These consistent visits ensure that laboratory results, such as blood cell counts, are monitored closely.
Transcranial Doppler (TCD) Screening
The Transcranial Doppler (TCD) ultrasound is a routine screening test used to measure the speed of blood flow in the brain’s major arteries. This non-invasive procedure is typically performed annually for children with severe SCD, starting at age two and continuing until at least age 16. Elevated blood flow velocity indicates a narrowing of the cerebral blood vessels, which is a significant predictor of stroke risk.
Emergency Action Plan
The care team should assist parents in developing a written Emergency Action Plan outlining the immediate steps to take if a crisis occurs. This plan must include clear instructions on when to seek immediate medical attention. Examples include the onset of sudden, severe pain or a fever of 101°F or higher.
Splenic sequestration is a life-threatening emergency typically seen in infants and young children. It occurs when blood pools rapidly in the spleen, causing a sudden drop in circulating blood cells and severe anemia. Parents are taught how to check for a rapidly enlarging spleen, which, along with paleness or a fast heart rate, requires immediate intervention.