A 29 year-old male with psoriasis and ulcerative colitis (UC) treated with adalimumab and mesalamine presented to the hospital with 3 weeks of abdominal pain, bloody diarrhea and a 20 pound weight loss. His symptoms started with 3 days of acute rectal pain that progressed to generalized abdominal pain accompanied by profuse bloody diarrhea with up to 15 stools per night. He also reported fevers, chills, and drenching night sweats. He was initially seen in an urgent care clinic where he was placed on high dose oral steroids for an UC flare and advised to follow-up with a gastroenterologist. After a week, his symptoms persisted and his gastroenterologist arranged for hospitalization. On admission, he was afebrile with normal vital signs but later spiked fevers to 39.2. Physical exam was significant only for lower abdominal tenderness without guarding or rebound tenderness. Lab studies showed normal chemistries and a mild leukocytosis (WBC 12,400). Hemoglobin was 12.7 after IV hydration. MRI of the abdomen showed blunted transverse folds with wall thickening and enhancement of the descending colon suggestive of active UC. A gastrointestinal stool pathogen panel (GI panel) was positive for Cryptosporidium. PCR testing for cytomegalovirus (CMV) was also positive. HIV test was negative. Colonoscopy revealed severe pancolitis with diffuse ulcers and numerous pseudopolyps. Biopsies were obtained and immunohistochemical staining revealed CMV inclusions. The patient was treated with a 3 day course of nitazoxanide for cryptosporidiosis and a 21 day course of valganciclovir for CMV. Adalimumab was discontinued and a steroid taper was initiated. The patient was seen in clinic 4 weeks after discharge. He reported complete resolution of his bloody diarrhea after treatment for his opportunistic infections.
Ulcerative colitis is relatively common condition that often follows a relapsing, remitting course. Many patients are on biologic agents to prevent flares. While these drugs improve overall quality of life, they increase the risk of opportunistic infections. Unfortunately, diarrheal illness due to opportunistic infections is impossible to distinguish from severe UC clinically and immunosuppressive therapy may be inappropriately intensified. Rapid identification of multiple pathogens from a single stool specimen can be achieved with GI panels that test for pathogen nucleic acids. GI panels are expensive but in our patient, the results played a pivotal role in the management by rapidly detecting Cryptosporidium resulting in immediate de-escalation of his immunosuppressive therapy and increased clinical scrutiny for co-infection with CMV.
Opportunistic infections are difficult to distinguish from ulcerative colitis flares but should always be considered in patients treated with biologic agents. GI panels expedite the recognition of these infections and the initiation of appropriate treatment.