Pneumonia or exacerbation of copd?

Case history: A 55-year-old obese woman presents with dyspnoea, increased production of green sputum, and low-grade fever. She has smoked for 35 years, one pack every day. A chest radiograph is equivocal for a new pulmonary infiltrate, due to her body habitus. What is the most likely diagnosis: acute pneumonia or an exacerbation of COPD? Chapter summary: From a clinical perspective, the distinction between pneumonia and exacerbations of COPD can be challenging. Chest radiography is often required to make the distinction, but its findings may be obscured by pre-existing conditions. Biomarkers have shown the most promise: both CRP and procalcitonin can reliably distinguish between COPD exacerbations and pneumonia, but further studies are required to make final recommendations on their use. Specific and distinctive inflammatory patterns in both pneumonia with concurrent COPD and exacerbations of COPD have been typified. Although they share some similarities, the cytokine profiles and macrophage activation are different in these conditions. Inhaled steroids are used widely in COPD and are associated with an increased risk for pneumonia but not for mortality, suggesting multiple underlying mechanisms.