Signs and Symptoms of Typhlitis (Neutropenic Enterocolitis)
Typhlitis presents classically with fever, abdominal pain (particularly in the right lower quadrant), and diarrhea in the setting of neutropenia (ANC <500 cells/mL), though this triad may be incomplete or absent in up to 12% of cases. 1, 2
Core Clinical Presentation
The cardinal features include:
- Fever (present in 48-84% of cases) 1, 3, 4
- Abdominal pain (81.8-91% of cases), which may be:
- Diffuse throughout the abdomen
- Localized to the right lower quadrant (cecal involvement)
- Potentially absent in patients receiving steroid therapy 1
- Diarrhea (42.9-72% of cases), which may be watery or bloody 1, 3, 4
- Nausea and vomiting 1
Physical Examination Findings
- Abdominal tenderness (82% of cases) 4
- Rebound tenderness in severe cases 5
- Decreased bowel sounds 5
- Guarding 5
- Abdominal distention 6
Critical Timing and Context
Typhlitis typically occurs 1-2 weeks after chemotherapy initiation, during the period of maximal mucosal damage and neutropenia 2. It is most common in:
- Leukemic patients
- Patients receiving high-dose myeloablative chemotherapy
- Patients treated with taxanes (even with non-myeloablative regimens) 1
Important Clinical Pitfalls
The "Classic Triad" May Be Absent
Up to 12% of patients with typhlitis are NOT neutropenic at presentation 4, and the condition has been documented in HIV patients with normal ANC 7. The absence of neutropenia should not exclude the diagnosis if clinical suspicion is high.
Steroid Masking
Pain may be completely absent in patients receiving concurrent steroid therapy, making diagnosis particularly challenging 1.
Progression to Sepsis
Sepsis is a common complication and may be the presenting feature 1. The most frequently isolated organisms are gram-negative Enterobacteriaceae, particularly Klebsiella pneumoniae 5, 3.
Associated Severe Manifestations
When present, these indicate advanced disease and higher mortality risk:
- Rectal bleeding or hematochezia 8, 7
- Hemodynamic instability 8
- Signs of perforation: pneumatosis intestinalis, free air 1
Diagnostic Confirmation
While not strictly "signs and symptoms," the diagnosis requires:
- Neutropenia (ANC <500 cells/mL or expected to fall below 500 within 48 hours) 1
- Bowel wall thickening >4 mm on imaging (CT or ultrasound) 1, 2
- Exclusion of other diagnoses (particularly C. difficile colitis, which can coexist) 1, 9
Bowel wall thickness >10 mm on imaging correlates with 60% mortality risk versus 4.2% with thickness ≤10 mm, making this a critical prognostic indicator 2.
High-Risk Ultrasound Findings
Beyond bowel wall thickening, these ultrasound signs indicate increased complication risk:
- Fluid-filled bowel
- Ascites
- Free fluid between bowel loops
- Hyperechoic septa floating in bowel lumen (representing necrotic mucosa) 2