Differential Diagnosis for Leukocytosis in a 28-year-old Male
Single Most Likely Diagnosis
- Viral upper respiratory infection: This is a common cause of leukocytosis, especially in a young adult. The presence of a mild increase in white blood cell count (WBC) with a predominance of neutrophils is consistent with a viral infection.
Other Likely Diagnoses
- Bacterial infection: Such as pneumonia, urinary tract infection, or skin infection, which can cause an increase in WBC with a predominance of neutrophils.
- Inflammatory condition: Like appendicitis, diverticulitis, or inflammatory bowel disease, which can also cause an increase in WBC.
- Stress or exercise-induced leukocytosis: Physical stress or intense exercise can cause an increase in WBC, especially neutrophils.
Do Not Miss Diagnoses
- Sepsis: Although less likely, sepsis is a life-threatening condition that requires prompt diagnosis and treatment. The presence of leukocytosis with a left shift (increase in immature granulocytes) would be more suggestive of sepsis, but it's essential to consider this diagnosis even with a mild increase in WBC.
- Acute leukemia: Although rare, acute leukemia can present with leukocytosis, and it's crucial to consider this diagnosis to avoid delayed treatment.
- Hematologic malignancy: Other hematologic malignancies, such as lymphoma, can also cause leukocytosis.
Rare Diagnoses
- Myeloproliferative neoplasm: Conditions like chronic myeloid leukemia (CML) or polycythemia vera can cause an increase in WBC, but these are relatively rare.
- Primary immunodeficiency: Certain primary immunodeficiencies can cause an increase in WBC, but these are rare and often present with other symptoms.
- Medication-induced leukocytosis: Certain medications, such as corticosteroids or lithium, can cause an increase in WBC, but this is relatively rare and usually associated with other symptoms or laboratory findings.