What are the diagnostic criteria for febrile neutropenia (fever with low neutrophil count)?

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From the Guidelines

Febrile neutropenia is diagnosed when a patient has a single oral temperature of ≥ 38.3°C (101°F) or a temperature ≥ 38.0°C (100.4°F) sustained over a 1-hour period and an absolute neutrophil count < 1,000/mL (equivalent to < 1.0 x 10^9/L) 1.

Diagnostic Criteria

The diagnostic criteria for febrile neutropenia include:

  • Fever: a single oral temperature of ≥ 38.3°C (101°F) or a temperature ≥ 38.0°C (100.4°F) sustained over a 1-hour period 1
  • Neutropenia: an absolute neutrophil count < 1,000/mL (equivalent to < 1.0 x 10^9/L), with severe neutropenia defined as < 500/mL (equivalent to < 0.5 x 10^9/L) and profound neutropenia defined as < 100/mL (equivalent to < 0.1 x 10^9/L) 1

Risk Assessment

Patients with febrile neutropenia can be stratified into high-risk and low-risk categories based on factors such as:

  • Duration of neutropenia: anticipated to last ≥ 7 days 1
  • Severity of neutropenia: absolute neutrophil count < 100 cells/mm^3 1
  • Presence of co-morbid medical problems: such as hemodynamic instability, oral or gastrointestinal mucositis, gastrointestinal symptoms, neurologic or mental-status changes, intravascular catheter infection, new pulmonary infiltrate or hypoxemia, or underlying chronic lung disease 1
  • Underlying cancer: such as acute leukemia 1
  • Intensity of chemotherapy: such as induction for acute leukemia or HSCT 1

From the Research

Diagnostic Criteria for Febrile Neutropenia

The diagnostic criteria for febrile neutropenia include:

  • Fever, defined as a single axillary temperature measurement of ≥37.5°C (oral temperature of ≥38.0°C) 2
  • Neutropenia, defined as a neutrophil count of <1000 cells/mm3 2 or an absolute neutrophil count (ANC) of <500 cells/mL 3
  • Absolute neutrophil count (ANC) of <1.5 × 10(9)/L is also considered neutropenia 4

Initial Evaluation

Initial evaluation of patients with febrile neutropenia includes:

  • A thorough history and physical examination 2
  • A complete blood cell count 2, 3, 5
  • Measurement of serum creatinine, blood urea nitrogen, transaminases, and C-reactive protein 2
  • Culture of blood (samples from a peripheral vein and/or catheter) 2
  • Urine culture is indicated in the presence of signs or symptoms of urinary tract infection, a urinary catheter in place, or abnormal results of urinalysis 2
  • Chest radiography is indicated for patients with respiratory signs or symptoms 2

Risk Classification

Proper risk classification should be performed using the Multinational Association for Supportive Care in Cancer (MASCC) scoring system to distinguish high-risk and low-risk patients with febrile neutropenia 3

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Clinical features of the neutropenic host: definitions and initial evaluation.

Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 2004

Research

[Pathophysiology and diagnosis of cancer patients with febrile neutropenia].

Gan to kagaku ryoho. Cancer & chemotherapy, 2013

Research

How I diagnose and treat neutropenia.

Current opinion in hematology, 2016

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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