Diagnostic and Management Errors in an Immunodeficient Patient with Pneumococcal Pneumonia with Bacteraemia due to Incorrect Assessment of the Patient’s Immune Status

A 79-year-old woman presented with fever and pleural chest pain. Based on the assessment of mild community pneumonia in an immunocompetent patient, outpatient follow-up was planned. However, the patient was admitted several hours later with a diagnosis of pneumococcal pneumonia with bacteraemia. In addition, selective immunoglobulin M deficiency was detected. In this case, although a history of recurrent osteomyelitis was provided, the physicians overlooked the information suggesting immunodeficiency, which led to an incorrect diagnostic and management decision. Obtaining the past medical history is essential, but utilizing it is even more important to avoid clinical decision-making errors.