Differential Diagnosis for High Fever, Leukopenia, and Anemia

Single Most Likely Diagnosis

• Viral Infections (e.g., HIV, EBV, CMV): These infections can cause high fever, leukopenia (particularly lymphopenia), and anemia due to bone marrow suppression or direct infection of hematopoietic cells.

Other Likely Diagnoses

• Bacterial Sepsis: Severe bacterial infections can lead to a systemic inflammatory response syndrome (SIRS) characterized by high fever, leukopenia (due to consumption of white blood cells), and anemia (from chronic disease or hemolysis).
• Malaria: Especially in endemic areas, malaria can cause high fever, anemia (due to hemolysis), and sometimes leukopenia.
• Autoimmune Disorders (e.g., Systemic Lupus Erythematosus): These conditions can lead to anemia of chronic disease, leukopenia (due to autoantibodies against white blood cells), and fever.

Do Not Miss Diagnoses

• Aplastic Anemia: A rare but potentially fatal condition where the bone marrow fails to produce blood cells, leading to anemia, leukopenia, and increased susceptibility to infections, which can present with fever.
• Severe Combined Immunodeficiency (SCID): Although rare, SCID can present with recurrent severe infections, fever, anemia, and leukopenia due to the lack of immune response.
• Tuberculosis: Especially in immunocompromised patients or those from endemic areas, TB can cause chronic fever, anemia of chronic disease, and leukopenia.

Rare Diagnoses

• Parvovirus B19 Infection: Can cause anemia (especially in individuals with hemoglobinopathies) and sometimes leukopenia, along with fever.
• Hematological Malignancies (e.g., Leukemia, Lymphoma): Although less common, these conditions can present with anemia, leukopenia (or leukocytosis), and fever due to bone marrow infiltration or systemic effects of the malignancy.
• Drug-Induced Agranulocytosis or Aplastic Anemia: Certain medications can cause severe leukopenia or bone marrow failure, leading to fever and anemia.