Differential Diagnosis
- Single most likely diagnosis
- Sickle Cell Disease: The presence of ovalocytes on the peripheral smear, microcytic anemia, and the patient's origin from Africa make sickle cell disease a strong consideration. The patient's symptoms such as widespread joint pain, unexplained weight loss, and night sweats can also be associated with sickle cell disease, especially if there are frequent crises or chronic complications.
- Other Likely diagnoses
- Thalassemia: Given the microcytic anemia (MCV 71) and high RDW (22.3), thalassemia is a plausible diagnosis. The patient's African origin also supports this, as thalassemia is prevalent in various parts of the world, including Africa. However, the presence of ovalocytes might lean more towards sickle cell disease or a compound heterozygous state for sickle cell and another hemoglobinopathy.
- Chronic Infections (e.g., Tuberculosis): The symptoms of night sweats, unexplained weight loss, and widespread joint pain could suggest a chronic infection. Given the patient's origin from Africa, where tuberculosis is more common, this becomes a consideration, especially with a low WBC count and microcytic anemia.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Malaria: Although the patient has been in the US (assuming, based on the context), malaria can present with similar symptoms (night sweats, weight loss, joint pain) and can cause anemia and thrombocytopenia. It's crucial to consider and rule out malaria due to its severity and the patient's African origin.
- Lymphoma: The combination of unexplained weight loss, night sweats, and joint pain could also suggest lymphoma, a diagnosis that would be critical to not miss due to its implications for treatment and prognosis.
- Rare diagnoses
- Other Hemoglobinopathies: Besides sickle cell disease and thalassemia, other hemoglobinopathies could present with similar laboratory findings and symptoms. These might include compound heterozygous states for different hemoglobinopathies.
- Autoimmune Hemolytic Anemia (AIHA): Although the direct Coombs test was not mentioned, AIHA could cause anemia, and some forms might present with microcytosis and a high RDW. However, the lack of positive autoimmune markers (e.g., RF, CCP antibody) makes this less likely.
- Paroxysmal Nocturnal Hemoglobinuria (PNH): A rare cause of anemia, thrombocytopenia, and sometimes hemolytic anemia, PNH could be considered but would typically require specific testing for diagnosis (e.g., flow cytometry for CD55 and CD59).