Subacute Dyspnea

We discussed at patient who came in with subjective fever and subacute cough and dyspnea found to have bilateral infiltrates on CXR without pleural effusions.  The patient was on leflunamide and humira for RA.  In this setting PJP was high on our differential. 

  1. How can you differentiate bacterial PNA and PJP?  In an HIV + population there is a comparison of bacterial pneumonia vs PJP.  If found 52% vs 32% with purulent sputum, 52% vs 32% with pleuritic chest pain, 15% vs 3% with pleural effusion, 54% vs 2 % with lobar consolidation and >7 days of fever/cough 20% vs 50% respectively. 

  2. Is there a serum test that can help diagnose PJP?  Yes, you can use a B-glucan, it is 92.5% sensitive and 64.6% specific, many of the false positives were seen in patients with invasive oral/esophageal candida.