Snapshot A 68-year-old woman presents to the emergency department due to fatigue, malaise, and a subjective fever. Her symptoms began approximately 1 week ago. Medical history is significant for small cell lung cancer recently treated with doxorubicin plus cyclophosphamide and etoposide. Her temperature is 102°F (38.9°C) and blood pressure is 100/80 mmHg. A complete blood count with differential is remarkable for an absolute neutrophil count of 320 cells/mm3. She is admitted to the hospital and administered intravenous cefepime. Introduction Definition a single fever of ≥ 101°F (38.3°C) in a patient with an absolute neutrophil count (ANC) < 500 cells/mm3 a sustained fever of ≥ 100.4°F (38°C) in a patient with an ANC of < 500 cells/mm3 Epidemiology Incidence commonly seen in patients receiving cytotoxic chemotherapy ETIOLOGY Pathophysiology chemotherapy impairs host immunity, predisposing the patient to infection Presentation Symptoms/physical exam fever tachycardia tachypnea Studies Initial testing includes complete blood count (CBC) with differential complete metabolic panel blood cultures urine culture culture of sites concerning for infection Other studies chest radiography in patients with respiratory findings a CT scan of the chest is typically ordered if chest radiography is unrevealing Treatment Medical high-risk patients (requires hospitalization) intravenous empiric antibiotics that cover for Pseudomonas aeruginosa medications cefepime piperacillin-tazobactam imipenem-cilastatin low-risk patients (can be treated as an outpatient) or patients with neutropenia without a fever oral empiric antibiotics medications oral ciprofloxacin levofloxacin amoxicillin-clavulanate Complications Sepsis syndrome Death Prognosis Delayed or inadequate empiric antibiotics leads to worse outcomes