Complications of Pediatric Sickle Cell

Sickle cell anemia is a genetic disease that causes the normal red blood cells to form a sickle shape during periods of deoxygenation. The main component of the disease is the erythrocytes (red blood cells) change from the normal discoid shape to that of a sickle shape. A sickle is a curved knife used to harvest grain (See above picture of a hammer and sickle). This sickling causes damage and blockages within the blood vessel. In the United States, sickle cell disease affects around 72,000 people, most of whom have African ancestors. Pediatric complications of sickle cell can be particularly serious.

Infections

The prevention of infections in sickle cell anemia is one of the main patient management goals. Because there is an increased incidence of pneumococcal disease in sickle cell patients, the American Academy of Pediatrics recommends that all children with sickle cell receive all vaccinations including those for pneumococcus and hepatitis B. Prophylactic daily penicillin is generally given from age 2 months to 5 years to help prevent infection; however, infections are still a threat.

Sickle Cell Crisis – Acute Pain

Sickle cell crisis (vaso-occlusive crisis) is the most common complication of sickle cell anemia in the pediatric population. The crisis has a three-day to two-week duration with associated pain generally located in the legs, back or abdomen and beginning at night. These episodes can be triggered by activities that cause decreased oxygenation such as exercise or high altitude; however, many times no trigger is apparent. The crisis can occur in the any of the organs and the symptoms will be reflective of that organ system.

Acute Chest Syndrome

Acute chest syndrome is considered a life-threatening complication that requires immediate medical evaluation. This syndrome can present at any age and is the most common complication associated with death. The sickle blood cells are causing blockages and damage in one or both lungs. The syndrome is associated with fever greater than 102 degrees, cough and/or wheezing, rapid respiration and/or difficulty breathing, and pain in the chest. Many times the syndrome is associated with an onset of an infection, and treatment is generally as an in-patient.

Stroke

After acute chest syndrome, stroke is the most common killer of patients older than age 3 with sickle cell disease, or around 10 percent of pediatric patients. Again, the sickle cells cause damage to the blood vessel walls which leads to thrombosis (a clot) and a resulting stroke. Many of these children will have multiple small strokes. Aneurysms are common in sickle cell patients and these can also lead to a stroke.

Pulmonary Hypertension

Pulmonary hypertension is an increase in the blood pressure within the pulmonary system. Pulmonary hypertension is life-threatening on both the short-term and long-term arenas and was once thought to be rare in the pedatric sickle cell patient; however, a 2004 study published by the American Society of Hematology has shown that pulmonary hypertension is highly prevalent in the pediatric population and increases with age. Respiratory failure is the result of sudden worsening pulmonary hypertension, and cor pulmonale is the end-stage of chronic (long-term) pulmonary hypertension. Cor Pulmonale is “heart disease” of the right side of the heart with right atrial and ventricular elevated blood pressure and enlargement of these chambers (right-sided cardiomegaly).

Anemia

Anemia is a significant characteristic of sickle cell disease and hence the name sickle cell anemia. Chronic anemia results from the shortened life span of the red blood cells following splenic removal. Since anemia is a normal symptom of the disease, one of the complications is the sudden worsening of the baseline “normal” anemia. Acute splenic sequestration is a distinct complication infants and young children. The erythrocytes are sequestered in the spleen which results in splenic pain, and its enlargement that can be felt below the left rib cage.

Kidney Problems

The kidney is particularly vulnerable to damage from the sickle cells. Non-symptomatic blood in urine, uncontrolled bed-wetting, and increased kidney infections are some of the earlier symptoms in children older than 5 years. Death in 10 to 15 percent of sickle cell patients is from kidney failure. Renal medullary carcinoma is a rare complication.

Priapism

Almost half of all males with sickle cell anemia, including children, suffer from priapism (a prolonged and painful erection). These erections can last from several hours to days. If priapism is not treated, partial or complete erectile dysfunction can occur.

Gallstones and Gallbladder Disease

About 30 percent of pediatric patients with sickle cell will have gallstones and acute symptoms have been since as young as 5 years of age. The gallstones pose no problem unless they trigger acute gallbladder disease which will require removal of the gallbladder.

Aplastic Crisis

Infants and children are susceptible to aplastic crisis which is a severe form of anemia associated with the cessation of the bone marrow producing erythrocytes. The anemia is severe enough to generally require transfusion, and the associated trigger is human parvovirus B19.

Cardiomegaly

Since most pediatric patients with sickle cell anemia have fewer erythrocytes to carry oxygen, the heart has to work harder to provide oxygen to the body. Invariably older children suffer from cardiomegaly (enlarged heart) with increase risk of heart failure and heart attack. Cardiomegaly is secondary to the overworking of the heart and an intrinsic cardiomyopathy caused by the sickling red blood cells.

Other Complications

Excessive production of the red blood cells in the bone marrow results in abnormally long bone and misshapen skulls. Sickling blocks oxygen to the bone which cause bone loss and pain and hand-foot syndrome in children. A condition called aseptic necrosis of the hip may require hip replacement. Children older than 10 are susceptible to otherwise unexplained leg sore and ulcers. The sickling red blood cells cause damage to the blood vessels in the eye. Blindness and detached retinas can result.

About this Author

Living in Gainesville, Ga., Dr. Marvin Phillips, known affectionately as Dr. Phil, obtained a Doctor of Medicine degree from the Medical College of Georgia. After a pediatric residency at the Medical University of South Carolina, he practiced pediatrics for nine years and retired in 1999. He has been writing since college and has published works in “Circulation Research” and “The Anatomical Record.”