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Febrile neutropenia
Fever in a patient with a neutrophil count below 500 is an emergency: take cultures and give broad-spectrum intravenous antibiotics covering Pseudomonas within an hour, without waiting for focal signs — because without neutrophils there is no visible inflammation.
Why it matters in the exam
The typical question presents a patient a few days after chemotherapy with a temperature of 38.3 degrees and very low neutrophils, often with no findings on examination. The candidate must remember the definition (neutrophils below 500, or expected to fall below 500 within 48 hours, with a single temperature of 38.3 or 38.0 sustained for an hour) and the first step: blood cultures (including from the line) and immediately an antipseudomonal beta-lactam — cefepime, piperacillin-tazobactam or meropenem — within 60 minutes.
Further questions test risk assessment and added treatment. A MASCC score of 21 or more defines low risk, allowing oral treatment (amoxicillin-clavulanate with ciprofloxacin) and even outpatient follow-up. Vancomycin is added only for specific indications: haemodynamic instability, line or skin infection, pneumonia, MRSA carriage or a Gram-positive blood culture. If fever persists for 4–7 days despite antibiotics, a fungus is sought (chest CT, galactomannan) and antifungal treatment is added. Preventive G-CSF is reserved for regimens with a risk of febrile neutropenia of 20% or more.
Key points
- Definition: neutrophils below 500 + temperature 38.3 (or 38.0 for an hour).
- Cultures and an antipseudomonal beta-lactam within 60 minutes.
- MASCC 21 or more = low risk, oral treatment possible.
- Vancomycin only for indications: instability, line, skin, lung, MRSA.
- Fever for 4–7 days → search for fungus and antifungal treatment.
Summary table
| Step | Criterion | Action | Exam note |
|---|---|---|---|
| Definition | Neutrophils below 500 + temperature 38.3, or 38.0 for an hour | Emergency | Also neutrophils expected to fall below 500 within 48 hours |
| First treatment | High risk | Cefepime, piperacillin-tazobactam or meropenem within 60 minutes | After blood cultures, without waiting for them |
| Low risk | MASCC 21 or more | Oral amoxicillin-clavulanate + ciprofloxacin | Close follow-up, outpatient possible |
| Adding vancomycin | Instability, line, skin, pneumonia, MRSA | Vancomycin | Not routine for every patient |
| Persistent fever | 4–7 days despite antibiotics | Chest CT, galactomannan, antifungal | Aspergillus, Candida |
| Prevention | Regimen risk 20% or more | G-CSF | Not routine for all chemotherapy |
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Sources
- ASCO/IDSA Guideline: Outpatient Management of Fever and Neutropenia in Adults Treated for Malignancy, 2018 — Risk assessment and outpatient therapy
- IDSA Clinical Practice Guideline for the Use of Antimicrobial Agents in Neutropenic Patients with Cancer, 2010 — Empirical antibiotic and antifungal therapy
- Harrison's Principles of Internal Medicine, 21st edition (2022) — Infections in Patients with Cancer
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-02. The text may contain errors; when in doubt, check the source.