09/11/2025
If a patient on steroids has a high neutrophil count (neutrophilia) and a low lymphocyte count (lymphopenia), it is most likely a drug effect and not necessarily a sign of a severe infection or underlying disease.
Steroids ⬆️ neutrophils: Corticosteroids cause a neutrophilia (increased neutrophil count). This is often due to demargination—they pull neutrophils that were stuck to the vessel walls back into the circulation—and a decreased exit from the bloodstream into tissues. It is not an indication of a new bacterial infection.
• but ⬇️ lymphocytes: Corticosteroids cause lymphopenia (decreased lymphocyte count) because they promote the apoptosis (programmed death) and sequestration (movement out of the bloodstream) of lymphocytes.