What is the management approach for a patient with leukocytosis (high White Blood Cell count)?

From the Guidelines

The management of high WBC (leukocytosis) should focus on identifying and treating the underlying cause, with initial steps including a thorough history and physical examination, followed by laboratory tests such as a complete blood count with differential, peripheral blood smear, and potentially bone marrow examination if a hematologic malignancy is suspected. For infection-related leukocytosis, appropriate antibiotics should be prescribed based on the suspected pathogen 1. For inflammatory conditions, anti-inflammatory medications may be indicated. If leukemia is diagnosed, treatment may include chemotherapy regimens specific to the type of leukemia, such as cytarabine plus an anthracycline for acute myeloid leukemia, or tyrosine kinase inhibitors like imatinib for chronic myeloid leukemia. For extreme leukocytosis (>100,000 cells/μL) causing leukostasis, emergency leukapheresis may be necessary to prevent complications like stroke or respiratory failure, and supportive care including hydration and allopurinol (300 mg daily) may be needed to prevent tumor lysis syndrome during treatment of hematologic malignancies 1. The approach varies significantly based on whether the leukocytosis is reactive (due to infection, inflammation, stress) or neoplastic (due to leukemia or other blood cancers), making accurate diagnosis crucial for appropriate management. In cases of hyperleukocytosis, hydroxyurea can be used to lower the WBC count, given at dosages up to 50 to 60 mg/kg per day, until WBCs are less than 10-20 10^9/L 1. It is essential to consider the most recent and highest quality studies when making management decisions, such as the 2019 recommendations from the European LeukemiaNet for the management of acute promyelocytic leukemia 1.

From the Research

Management Approach for Leukocytosis

The management approach for a patient with leukocytosis (high White Blood Cell count) involves several steps:

• Evaluating the patient's symptoms and medical history to determine the underlying cause of the leukocytosis 2
• Conducting a physical examination to identify signs of infection, inflammation, or other conditions that may be contributing to the leukocytosis 2
• Ordering laboratory tests, such as a complete blood count (CBC) with differential, to confirm the diagnosis and identify any abnormalities in the blood cells 2, 3
• Considering the patient's age, pregnancy status, and other factors that may affect the normal range for white blood cell count 2
• Looking for signs of infection, such as fever, chills, or localized redness and swelling, and treating the infection promptly if present 2, 3
• Evaluating the patient for other potential causes of leukocytosis, such as medication use, stress, or underlying medical conditions 2, 3
• Referring the patient to a hematologist or oncologist if a malignant cause is suspected or if the leukocytosis persists or worsens despite treatment 2

Potential Causes of Leukocytosis

Some potential causes of leukocytosis include:

• Infections, such as bacterial or viral infections 2, 3
• Inflammatory conditions, such as arthritis or asthma 2, 3
• Medications, such as corticosteroids or beta agonists 3
• Stress, such as physical or emotional stress 2, 3
• Underlying medical conditions, such as leukemia or lymphoma 2, 3
• Other conditions, such as appendicitis or other surgical conditions 4

Diagnostic Tests

Diagnostic tests that may be used to evaluate leukocytosis include:

• Complete blood count (CBC) with differential 2, 3
• Blood smear 2
• Bone marrow biopsy or aspiration 3
• Imaging studies, such as X-rays or CT scans 3
• Other laboratory tests, such as blood cultures or serology tests 3

Treatment

Treatment for leukocytosis depends on the underlying cause and may include:

• Antibiotics for bacterial infections 2, 3
• Antiviral medications for viral infections 3
• Anti-inflammatory medications for inflammatory conditions 2, 3
• Medications to manage stress or underlying medical conditions 2, 3
• Surgery or other interventions for conditions such as appendicitis or other surgical conditions 4
• Referral to a hematologist or oncologist for malignant causes 2