Absence of leukocytosis in bacteraemic pneumococcal pneumonia

Evaluation of patients with respiratory symptoms in primary care medicine is often based on peripheral WBC count that dictates the extent of diagnostic investigation. A normal WBC count may result in a limited investigation, often omitting chest radiography.

To determine the extent to which patients hospitalised with bacteraemic pneumococcal pneumonia have no leukocytosis at presentation.

A retrospective analysis was performed of patients with bacteraemic community-acquired pneumococcal pneumonia from 2000 to 2007 in a community care academic medical centre. Records were reviewed for symptoms, signs, and laboratory data including pneumococcal serotypes, chest radiographs on admission, and outcome.

21% of the patients presented with a normal WBC count (16.7% of the children and 25.6% of the adults). Among this population with a normal WBC count at presentation, 90% of the adults and 70% of the children developed leukocytosis within a few days after admission.

In this study, in as many as one-fifth of all the patients with bacteraemic pneumococcal pneumonia, there was no leukocytosis at presentation. We therefore suggest that every patient with clinically suspected pneumonia should undergo chest radiography even if the WBC count is normal.