Leukocytosis and Leukopenia

Alterations in leukocytes are most commonly attributable to changes in the neutrophil concentration. Neutrophilia is most commonly seen in cases of inflammation. Evaluation for the presence of a left shift and toxic changes adds important etiological and prognostic information. Differentiation between inflammatory, stress, and excitement leukograms is described. Leukocytosis due to other cell lines and neoplastic cells is also briefly discussed. Neutropenia is most commonly seen due to decreased production of cells by the bone marrow (e.g. secondary to infectious agents, drug/toxin exposure, neoplasia) or increased peripheral utilization, in response to acute inflammatory processes. Treatment considerations for cases of leukocytosis and leukopenia are discussed.