A 70-year-old woman with a background of CD of the terminal ileum for 21 years. She had undergone limited right hemicolectomy, 20 years prior to presentation; however, she experienced postoperative recurrence of the condition, for which she was on azathioprine 50 mg and prednisolone 5 mg for 10 years. Despite this, she presented with a history of worsening abdominal pain and diarrhea. After undergoing the standard screening test for TB (chest X-ray [CXR] and tuberculin skin test), she was commenced on 3 doses of infliximab (IFX). However, 4 weeks following the third infusion, she presented with persistent pyrexia of unknown origin. She was initially treated with intravenous cefuroxime but continued to be pyrexial. Blood cultures grew Cryptococcal neoformans as well as Klebsiella pneumoniae. Cerebrospinal fluid examination also confirmed the presence of cryptococcal antigen. The patient was initially treated with amphotericin B, which was then switched to voriconazole. She was also commenced on intravenous cefuroxime and metronidazole. After 2 weeks, however, she presented with increasing shortness of breath and was found to be hypoxic. A repeat CXR revealed mild interstitial shadowing. CT image of the chest revealed pneumonia of the right lung and multiple shadows (Fig. 1). The patient was diagnosed by infectious disease specialists with possible Pneumocystis jiroveci pneumonia, for which she was commenced on co-trimoxazole. She had a complicated course, but she was finally discharged after 4 weeks on prednisolone 10 mg and co-trimoxazole. She appeared to be stable 1 month after discharge. However, she was readmitted 3 months later owing to relapse of her diarrhea. Blood culture during this admission showed no organisms; moreover, her stool was negative, even for Clostridium difficile. She was treated with intravenous hydrocortisone. However, she developed sudden cardiorespiratory arrest and died. A post-mortem was not carried out.

A 68-year-old man with a history of CD of the terminal ileum for 21 years. He had undergone 4 previous surgeries for CD of the terminal ileum. His condition recurred after the operation (abdominal pain, diarrhea, and weight loss), which was confirmed endoscopically (Fig. 2). He was initially commenced on azathioprine 50 mg a day and prednisolone 40 mg a day; however, he failed to achieve clinical remission after 4 weeks of therapy. IFX was added owing to a suboptimal response and the history of multiple surgeries. Pre-therapy screening for TB (CXR and T-SPOT. TB test) was negative, and the patient received 3 infusions of IFX. His CS was tapered after the first infusion of IFX by 5 mg/wk, as per our general protocol. He responded very well to the treatment and achieved clinical remission. However, 3 days after his third infusion, he presented with pyrexia of unknown origin. He was initially treated with intravenous ceftriaxone but failed to respond and was transferred to the intensive care unit (ICU) with septicemic shock and multiorgan failure. CT imaging of the abdomen revealed disseminated micro-abscesses of the liver and spleen (Fig. 3). Biopsy of the liver abscess showed the presence of AFB, confirming the diagnosis of TB and active CD. Unfortunately, this patient also experienced bleeding after splenic biopsy and underwent a laparotomy to secure hemostasis. He had a prolonged stay in the ICU (4 weeks), but was eventually discharged. However, he remained unwell after discharge, with persistent diarrhea from active CD and progressive weight loss from ongoing active TB. He was on a small maintenance dose of prednisolone (10 mg) and anti-TB treatment, but azathioprine was discontinued owing to neutropenia. Although he continued to have symptoms of CD, he was deemed unfit for surgery. The patient was admitted 8 months later with worsening symptoms (diarrhea, abdominal pain, and weight loss), and stool culture during this admission grew nontyphoidal Salmonella. He was provided nutritional support and antibiotic therapy. However, he developed nosocomial pneumonia, and despite treatment with intravenous piperacillin/tazobactam, he died 2 weeks later.

A 61-year-old woman with Crohn's colitis for 6 years. She had chronic active disease despite being on maintenance therapy with azathioprine and sulfasalazine, requiring multiple courses of prednisolone. She subsequently developed a perianal fistula as well as a colovesical fistula, with recurrent urinary tract infections. Subsequently, it was decided to start her on IFX. She initially showed remarkable improvement; however, 5 weeks after her fourth dose, she developed bloody diarrhea and discharge from the perianal fistula. A colonoscopy was not carried out to rule out cytomegalovirus (CMV) colitis. Owing to the flare of her CD, the patient was started on intravenous hydrocortisone while awaiting stool cultures. However, empirical antibiotics were not commenced as she had no fever and the clinical presentation was similar to that during her previous flares. However, her stool culture subsequently isolated V. cholera and she was also commenced on tetracycline. She improved clinically and was discharged after 5 days. However, she was re-admitted 3 days later owing to shortness of breath. On this admission, she was in septicemic shock and respiratory distress, requiring intubation. Chest radiograph showed widespread lung consolidation suggestive of atypical pneumonia. The patient subsequently died as a result of severe bronchopneumonia despite aggressive treatment with intravenous piperacillin/tazobactam.