Neutrophilia
March 30th, 2020
Overview
Neutrophilia is the presence of increased circulating neutrophils, and is a common finding in the full blood count of acutely unwell patients.
Aetiology
- Neutrophilia is classically caused by bacterial infection (or in fact any pyogenic infection), though there are several other important causes. Inflammation of any cause may result in neutrophilia, including the post-surgical state, burns and autoimmune disease. Long-term smoking can also cause a chronic low-grade neutropaenia.
Acute stress or exertion can cause shift of neutrophils into the circulation, resulting in pseudoneutrophilia. Corticosteroids may cause neutrophilia through demargination of neutrophils from the endothelial lining, delayed migration from the circulation into tissues and delayed apoptosis. After splenectomy patients will develop neutrophilia.
Myeloproliferative disorders are a less common cause of neutrophilia that are important not to miss.
Causes of Neutrophilia
- Pseudoneutrophilia (granulocyte shift) - vigorous exercise, emotional stress, vomiting, seizure, paroxysmal tachycardia
- Acute infection (particularly pyogenic) - bacterial, viral, fungal, parasitic
- Inflammation - e.g. surgery, burns, infarction, autoimmune disease
- Corticosteroids
- Myeloproliferative neoplasms - CML, polycythaemia, essential thrombocytosis
- Solid tumours
- Post splenectomy
- Heavy smoking
Pearls
- Neutrophilia should be correlated with the patient's clinical state and other markers of inflammation
- Most often the history and examination will reveal the most likely cause of neutrophilia
- Neutrophilia with left shift of granulocytes on blood film is highly suggestive of acute bacterial infection
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