Differential Diagnosis for Monocytosis with Anemia and Thrombocytopenia in a Toddler
Single Most Likely Diagnosis
- Viral Infection: Many viral infections, such as Epstein-Barr virus (EBV), cytomegalovirus (CMV), and human herpesvirus 6 (HHV-6), can cause monocytosis, anemia, and thrombocytopenia in toddlers. These infections are common in this age group and can lead to bone marrow suppression, resulting in the observed laboratory findings.
Other Likely Diagnoses
- Bacterial Infection: Certain bacterial infections, such as tuberculosis or brucellosis, can cause monocytosis, anemia, and thrombocytopenia. These infections can lead to bone marrow involvement, resulting in the observed laboratory abnormalities.
- Autoimmune Disorders: Conditions like systemic lupus erythematosus (SLE) or rheumatoid arthritis can cause monocytosis, anemia, and thrombocytopenia due to autoimmune-mediated bone marrow suppression.
- Nutritional Deficiencies: Deficiencies in nutrients like vitamin B12 or folate can cause anemia and thrombocytopenia, and may also lead to monocytosis.
Do Not Miss Diagnoses
- Leukemia: Although less common, leukemia (e.g., acute myeloid leukemia or acute lymphoblastic leukemia) can present with monocytosis, anemia, and thrombocytopenia. Missing this diagnosis can have devastating consequences, making it essential to consider and rule out leukemia with appropriate testing.
- Lymphoma: Similar to leukemia, lymphoma can cause bone marrow involvement, leading to the observed laboratory findings. Prompt diagnosis and treatment are crucial to prevent serious complications.
- Severe Chronic Diseases: Conditions like chronic kidney disease or liver disease can cause bone marrow suppression, resulting in monocytosis, anemia, and thrombocytopenia.
Rare Diagnoses
- Histiocytosis: Rare conditions like Langerhans cell histiocytosis can cause bone marrow involvement, leading to monocytosis, anemia, and thrombocytopenia.
- Storage Diseases: Certain storage diseases, such as Gaucher disease, can cause bone marrow involvement and result in the observed laboratory findings.
- Congenital Disorders: Rare congenital disorders, such as congenital amegakaryocytic thrombocytopenia, can cause thrombocytopenia and may also be associated with monocytosis and anemia.