Pneumocystis jiroveci pneumonia in a patient taking Benepali for rheumatoid arthritis

We present a case of a 57-year-old woman who contracted Pneumocystis jiroveci pneumonia while on Benepali, the biosimilar version of etanercept for rheumatoid arthritis. She had seropositive erosive disease. She was admitted to clinic with a 2-week history of dyspnoea, dry cough and fever. Her initial examination showed her to be hypoxic on air with saturations of 77% and left basal crackles. Her admission chest X-ray showed fine reticular shadowing, with an initial suspicion of pulmonary fibrosis. She was empirically treated for community-acquired pneumonia but continued to deteriorate with a worsening type 1 respiratory failure. She was intubated and ventilated on intensive care. The suspicion was raised of P. jiroveci pneumonia given her immunosuppression, hypoxic presentation and chest X-ray changes. This was confirmed on sputum PCR. She was treated with a 3-week course of steroids and co-trimoxazole. She was discharged home after a 2-week admission.