Synopsis
Grade neutrophil deficiency, recognise infection despite muted signs, identify drug, immune, nutritional, infective and marrow causes, and stop culpable exposure while supporting safe recovery.
- Neutropenia is a reduced absolute neutrophil count, commonly graded as mild 1.0–1.5, moderate 0.5–1.0 and severe below 0.5 × 10^9/L, with context and duration determining risk.
- Agranulocytosis usually denotes profound neutropenia, often drug induced, with a high risk of rapidly progressive bacterial or fungal infection.
- Repeat an unexpected result and inspect the film, but treat fever or physiological instability immediately rather than waiting to prove persistence.
Key red flags
Hypotension, confusion, raised lactate or hypoxia with neutropenia needs immediate antibiotics and organ support regardless of temperature.
Investigation priorities
Confirm severity and detect other lineage or morphological clues.
Management branches
A low neutrophil count is newly reported or found during illness.
- Assess temperature, haemodynamics, mucosa, skin, lines, respiratory and perianal symptoms immediately and treat septic physiology through the acute pathway.
- Repeat count and film, retrieve prior values and grade depth and duration while taking cultures and giving antibiotics when fever or instability is present.
Key medicines
FilgrastimHaematology or oncology uses a weight-based subcutaneous regimen for a defined chemotherapy, congenital or severe drug-related indication, adjusting duration to neutrophil recovery and clinical context.
Culprit medicine withdrawalWithhold further doses immediately under the product-specific agranulocytosis pathway and do not rechallenge unless a national monitoring service and senior specialist explicitly authorise it.