Approach to the adult with unexplained neutropenia
- Nancy Berliner, MD
Nancy Berliner, MD
- Professor of Medicine
- Harvard Medical School
- Chief, Division of Hematology
- Brigham and Women's Hospital
- Section Editors
- Laurence A Boxer, MD
Laurence A Boxer, MD
- Section Editor — White Cell Disorders
- Henry and Mala Family Professor of Pediatric Hematology/Oncology
- University of Michigan
- Reed E Drews, MD
Reed E Drews, MD
- Section Editor — Complications of Cancer
- Associate Professor of Medicine
- Harvard Medical School
Neutrophils are mature granulocytic white blood cells (WBC) that defend against infection. Neutropenia is an abnormally low number of circulating neutrophils, which is based on a calculated number from a complete blood count (CBC). (See 'Terminology and definition of neutropenia' below.)
The implications of neutropenia vary widely, from a risk of potentially life-threatening infections in drug-induced neutropenia to a benign finding with essentially no clinical implications in individuals with benign ethnic neutropenia. Thus, it is important to determine the cause of neutropenia, and the associated infectious (and other) risks, so that patient can be appropriately managed and educated about his/her condition.
This topic will discuss our approach to the evaluation of the adult patient with unexplained neutropenia as a predominant feature of the CBC. The approach to the patient with neutropenia in the setting of other major cytopenias (eg, anemia, thrombocytopenia) is discussed separately. (See "Clinical manifestations and diagnosis of the myelodysplastic syndromes" and "Aplastic anemia: Pathogenesis; clinical manifestations; and diagnosis".)
The management of non-chemotherapy-induced neutropenia is presented separately. (See "Management of the adult with non-chemotherapy-induced neutropenia" and "Overview of neutropenia in children and adolescents", section on 'General aspects of treatment'.)
Fever in a patient who is neutropenic due to chemotherapy, hematopoietic cell transplant, or bone marrow suppression from any cause is a medical emergency. This issue is discussed separately. (See "Overview of neutropenic fever syndromes".)
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- TERMINOLOGY AND DEFINITION OF NEUTROPENIA
- MAJOR CAUSES OF NEUTROPENIA
- Benign ethnic neutropenia
- Congenital neutropenias
- Acquired neutropenias
- Hospitalized patient
- DETERMINING THE CAUSE
- Overview of evaluation
- - Family and patient history
- - Medication history
- - Infection history
- Physical examination
- - Signs of an underlying disorder
- - Signs of active infection
- Laboratory testing
- - Laboratory records
- - Other cytopenias
- - Additional laboratory testing
- Distinguishing infection-induced from drug-induced neutropenia
- Trial of drug discontinuation
- FURTHER EVALUATION AND MONITORING
- Monitoring the ANC
- Determining risk of infection
- Hematologist referral
- Who needs a bone marrow evaluation?
- Indications for hospital admission
- INFORMATION FOR PATIENTS