The patient is admitted to the hospital for a 5-day history of diffuse myalgias, cough, diarrhoea and fever peaking at 100.8°F (38.2°C). Medical history is significant for systemic lupus erythematosus (SLE), managed with hydroxychloroquine 400 mg daily, mycophenolate mofetil 500 mg two times a day and prednisone 5 mg daily. Laboratory tests are provided in table 1.

Laboratory values

Chest radiography identified interstitial opacities in the right upper lung field, indicative of pneumonia. Consequently, treatment with amoxicillin-clavulanic acid and doxycycline was initiated. During hospitalisation, the patient developed severe abdominal pain, was refractory to opioid analgesics and had exacerbated diarrhoea. A physical examination revealed generalised abdominal tenderness. To elucidate …