Question

A 9-year-old African American female presents to the emergency room with a 4-hour history of "strange behavior." Her stepmother states that she appears "dazed," and she refuses to walk. She and her siblings have all had "colds" with clear rhinorrhea, sore throats, and non-productive coughs. She has "no appetite," but she has been drinking fluids "fairly well." She has had low-grade fevers up to 99.0°F orally and no history of true fevers. Otherwise, she has been well. Her stepmother denies a history of significant health problems. She states that her daughter takes a daily multivitamin and daily penicillin VK tablet. Her immunizations are up to date. She has a history of normal growth and development. Family history is significant for several family members who have a history of gallstones and a cousin who receives frequent blood transfusions.

On exam, patient is a well appearing with no evidence of fluctuating consciousness or cardiorespiratory distress. Vital signs are stable. Her HEENT exam is significant for clear rhinorrhea. Cardiovascular exam demonstrates a 2/6 systolic ejection murmur. Abdominal exam demonstrates a palpable spleen 4 cm below the left costal margin. Her neurologic exam is significant for unilateral, same-sided weakness of her upper and lower extremity. She is unable to move the impaired arm or leg. She demonstrates no evidence of pain with involuntary movement of any of her extremities. The remainder of her exam is unremarkable.
Available laboratory studies demonstrate a WBC of 15,000 cells/mc, Hb 10 gm/dL platelet count 250,000 per μl (microliter) of blood and peripheral blood smear demonstrates many target cells and one crescent shaped cell reported. Other laboratory studies are pending at this time.

The most likely underlying cause of this patient's signs and symptoms is:

Answer 1

The most likely cause of the 9-year-old patient's symptoms, including unilateral weakness, target cells, and splenomegaly, is sickle cell disease.

Step-by-step explanation:

The most likely underlying cause of the signs and symptoms in the 9-year-old patient is sickle cell disease (SCD). The findings of a splenomegaly (enlarged spleen), a systolic murmur, and unilateral weakness alongside the presence of both target cells and a crescent-shaped cell on the peripheral blood smear are suggestive of this diagnosis. The penicillin VK prophylaxis and the cousin requiring frequent blood transfusions hint at a family history of hemoglobinopathies, which includes SCD. The stepmother's account of the child's low-grade fevers and recent cold-like symptoms, along with the absence of significant health problems, could be consistent with the effects of SCD on the immune system. The presence of a hemoglobin level of 10 g/dL, elevated WBC count, and target cells strengthens the suspicion for SCD as the underlying cause of the observed symptoms, including the painless unilateral weakness.