146 Infectious Disease and Foreign Travel Emergencies
Neutropenia has a significant generalized infection risk with a temperature
>100°F (38°C) in patients with an absolute neutrophil count <0.5 109 /L, or
<1.0 109 /L if the count is rapidly falling.DIAGNOSIS1 Neutropenic patients may already know their diagnosis and/or be receiving
treatment, or can present as a new case.
2 Causes of neutropenia include:
(i) Reduced neutrophil production:
(a) aplastic anaemia
(b) leukaemia, lymphoma
(c) myeloproliferative syndrome
(d) metastatic bone marrow disease
(e) drug-induced agranulocytosis, including chemotherapy
(f) megaloblastic anaemia crisis.
(ii) Reduced neutrophil survival:
(a) systemic lupus erythematosus (SLE)
(b) immune-mediated
(c) drug-related
(d) Felty syndrome.
(iii) Reduced neutrophil circulation:
(a) septicaemia
(b) hypersplenism.
3 Ask about constitutional symptoms including fever and malaise, plus organ-
specific features such as cough, frequency and dysuria, diarrhoea or
headache and confusion.
(i) Take a detailed drug history, contact and travel history.
4 Record the vital signs and note any focal sources of sepsis including the skin,
ears, throat and perineum, indwelling catheters, and for evidence of anaemia
or bruising suggesting a pancytopenia.
5 Establish venous access with strict asepsis, and send blood for full blood
count (FBC), coagulation profile, electrolyte and liver function tests (ELFTs)
and two sets of blood cultures from different venepuncture sites.
6 Request a chest radiograph (CXR) and send a midstream urine (MSU) sample.MANAGEMENT1 Start empirical antibiotic therapy initially, unless there is a clear focus of
infection, and discuss with an infectious disease physician or microbiologist.