Neutropenia in primary care.

#### Learning points A mild neutropenia of 1.2×109/L is detected in a 69 year old man who presents with a short history of fatigue. He takes no regular drugs. The rest of his blood count is normal, as is his physical examination. Neutropenia is defined as an absolute neutrophil count of less than 1.5×109/L. It is important for two reasons. Firstly, it may indicate an underlying systemic or haematological disease. Secondly, it reflects an increased risk of life threatening bacterial infection—risk increases once the count is less than 1.0×109/L and becomes even greater in severe neutropenia (box).1 2 #### Severity of neutropenia The General Practice Research Database suggests that 1:100 000 patients per year receive an ICD (International Classification of Diseases) code for neutropenia or agranulocytosis.3 Although data are limited, we can assume that many more have transient or mild neutropenia. The more severe the neutropenia, the more likely it is that further investigation will be initiated, although no strict guidelines exist for this. Table 1⇓ highlights important causes of isolated neutropenia. View this table: Table 1 Important causes of acquired neutropenia …