J Hosp Med

How high can WBC counts rise with corticosteroid therapy?

April 24, 2025

Study details: This retrospective cohort study analyzed 28,425 nonsurgical patients admitted to a large healthcare system from 2017 to 2018. Patients were excluded if they had immunosuppression, infection, malignancy, or corticosteroid use within 2 weeks before admission. The increase in white blood cell (WBC) count following corticosteroid administration was measured, stratified by corticosteroid dose.

Results: WBC response peaked at 48 hours after corticosteroid administration, with a mean increase of 2.4 × 10⁹/L WBCs. The mean increase varied by dose:

• 0.3 × 10⁹/L for low-dose corticosteroids
• 1.7 × 10⁹/L for medium-dose
• 4.84 × 10⁹/L for high-dose

In contrast, patients not receiving corticosteroids showed a decrease in WBC count during hospitalization.

Clinical impact: Clinicians should anticipate an increase in WBC count up to 4.84 × 10⁹/L within 48 hours of high-dose corticosteroid administration. Larger increases or any rise following low-dose corticosteroids may indicate other causes of leukocytosis, aiding in differential diagnosis.

Source:

Sullivan E, et al. (2025, April 15). J Hosp Med. Elevation in white blood cell count after corticosteroid use in noninfected hospitalized patients. https://pubmed.ncbi.nlm.nih.gov/39932209/