Differential Diagnosis for a 3-year-old Girl with Severe Anemia
- Single most likely diagnosis:
- Thalassemia: The patient's extremely low hemoglobin level (1.4 g/dL), low MCV (50.5 fL) indicating microcytic anemia, and the absence of other obvious causes of anemia (e.g., blood loss, jaundice) make thalassemia a strong consideration. Thalassemia major often presents in the first two years of life with severe anemia, and the liver enlargement (liver edge palpable 2-3 cm below the right costal margin) could be due to extramedullary hematopoiesis, a common finding in thalassemia major.
- Other Likely diagnoses:
- Iron deficiency anemia: Although less likely given the severity of the anemia and the presence of other signs (e.g., liver enlargement), iron deficiency anemia is a common cause of microcytic anemia in children. However, the severity of anemia in this case (Hb 1.4 g/dL) is unusual for iron deficiency alone.
- Autoimmune Hemolytic Anemia (AIHA): This condition could explain the severe anemia but typically presents with jaundice and an elevated indirect bilirubin, which are not mentioned. The presence of a high WBC count with a left shift (indicative of infection or inflammation) and the absence of blasts on the peripheral blood smear (PBS) do not strongly support AIHA.
- Do Not Miss diagnoses:
- Sickle Cell Disease with severe anemia: Although the patient does not have the typical symptoms of sickle cell crisis (e.g., pain episodes), severe anemia can occur, especially if there's a superimposed infection. The absence of jaundice and the specific mention of no hemolysis signs make this less likely, but it's crucial not to miss due to its severity and the need for specific management.
- Severe infection leading to anemia: The patient's high fever, elevated WBC count, and respiratory symptoms suggest a severe infection, which can lead to anemia of chronic disease or a hemophagocytic lymphohistiocytosis (HLH) in rare cases. The absence of specific signs of infection causing anemia (e.g., hemolysis) makes this less likely but not impossible.
- Rare diagnoses:
- Congenital dyserythropoietic anemia: These are rare disorders characterized by ineffective erythropoiesis and could present with severe anemia. However, they are less common and typically have distinctive morphological features on bone marrow examination.
- Other hemoglobinopathies: Besides thalassemia and sickle cell disease, other hemoglobinopathies could cause severe anemia, though they are less common and might have specific clinical or laboratory features that are not mentioned in the case description.