Low neutrophils count is a frequent problem seen in day-to-day general practice. Most referrals to Haematology ( with isolated mild neutropenia ) are returned with an advice to monitor and further investigations. This chart on A4Medicine is to help clinicians manage and monitor patients with mild isolated neutropenia who do not have any other features to suggest a serious underlying cause. Febrile neutropenia is also discussed with an emphasis on early recognition and immediate referral. Further investigations to assess neutropenia are mentioned – once completed they can be included in the referral letter

Absolute neutrophil count ( ANC ) < 1.5 x 109 May suggest an underlying systemic or haematological disorder Increased risk of infections

Common incidental finding in primary care – often
○ drug induced
○ acute viral infection
 Agranulocytosis usually used to describe a more severe subset of neutropenia – count less than 0.2 
Carries risk of severe life threatening infections with susceptibility to opportunistic organisms
 Risk of infection is more severe when neutropenia is due to impaired production from chemotherapy or marrow failure
 Persons of African descent often have lower than normal neutrophil count

Decreased or ineffective production Accelerated turnover in blood Dislocation of shifts of cells from circulating to the marginal blood pools Unclear or combination of more than one mechanism ( eg thyroid dysfunction) .Rare for primary 
haematological malignancy to present with isolated neutropenia ( other cell 
lines are usually also 
affected )

Transient- Commonly associated with viral infections Eg EBV causing infectious mononucleosis is a very common cause ( see below ) Overwhelming bacterial infection can also deplete bone marrow reserves Chemotherapy agents Inflammatory and autoimmune conditions Drugs ( see below )

chronic- Less than 1.5 lasting > 3 months Can be a normal variant with people in good health- periodic FBC testing may indicate if 
○ any other haematological abnormality present
○ evidence underlying infection
○ inflammatory or malignant disease A count of < 0.5 – warrants an indepth evaluation Important to consider the condition when the sample was obtained
( count may vary considerably over short period of time , activity , exercise , eating etc )
○ take several measurements

Generally regarded as presence of a fever > 38° with an absolute neutrophil count of
 < 1.0 x 109

Result of bone marrow suppression- common SE of chemotherapy Risk of life threatening infections Most common complication of cancer chemotherapy Risk infection -consider in any systemically unwell patient receiving chemotherapy even if no fever present Risk increases with
○ age
○ advanced stage of disease
○ comorbidities
○ haematological malignancy
○ previous episode of febrile neutropenia
○ combined chemo-radiotherapy
○ poor nutritional status
○ Female 
○ Hb < 12
○ open wound or active infections
 Cases continue to be missed on initial presentation
○ not considered
○ patient may not disclose
○ lack of access to medical records
○ inability to mount an adequate inflammatory response – ie signs and symptoms may be minimal ( providing false reassurance ) Detailed history
○ nature of chemotherapy , which cancer
○ timing may give guidance on risk- although
 often unpredictable and should not be relied on
○ prior prophylactic antibiotics
○ concomitant steroid use 
( suppressed inflammatory response )
○ recent surgery Haematological malignancies can cause myelosuppression in patient even without chemotherapy


Presentation can be vague or with minimal symptoms
○ feeling hot or cold
○ rigors
○ sweats
○ flu like illness
○ general malaise Check for sore mouth and diarrhoea
 ( mucositis ) Do not wait for 
result of an urgent
 FBC – patients may decompensate 
rapidly Aim to determine how unwell the patient is Temp Signs of shock Focus of infection ( often not apparent ) If central line- check for signs of infection refer immediately- patients should 
receive IV antibiotics within 60 mins

Medical and family history ( heritable defects ) H/O recurrent infections Ask about oral inflammations
○ mouth ulcers
○ gingivitis
○ periodontitis
○ tooth loss , replacement Recurrent sinusitis and otitis Symptoms of pneumonia Perirectal pain and irritation

R/O Infection and Drug related causes Blood film Further tests- decide on individual basis Chronic viral serology Antinuclear antibodies and Rheumatoid factor Serum Immunoglobulin 
( Ig)Antineutrohil antibodies B12 , Folate , Iron , Ferritin TFT , LFT , HIV – if risk factors presentUs&Es if drug related -usually 
mild. -moderate decide on
 basis
 of risks/ benefit of treatment whether to continue the
 drug or not.- if continued 
monitor 
carefully Severe cases of 
drug related neutropenia ie < 0.1 discontinue
 the drug

Suggestion of progressive or serious disease of any kind Bone marrow disorder suspected
○ eg anaemia and thrombocytopenia develops with pre-existing neutropenia Severe neutropenia with a downward trend in absolute neutrophil count Consistent neutropenia < 1.0