Introduction: 5-aminosalicylic acid (mesalamine) rarely induces hypersensitivity. It is first line therapy for treatment of ulcerative proctitis. However, the journal of gastroenterology and hepatology states 12% of patients are unable to tolerate mesalamine or other compounds of 5-aminosalicylic acid. The most common side effects are identified as headache, nausea, abdominal pain, and mild watery diarrhea. This case report highlights the importance of recognizing mesalamine hypersensitivity in patients with ulcerative colitis.
Case Description/Methods: A 62-year-old man with history of hypertension, hyperlipidemia, chronic kidney disease stage 3B and ulcerative proctitis presented to the ED with abdominal pain (intensity 9/10), rectal pain, tenesmus, flatulence, persistent bloating, and bright red blood per rectum of 2 months duration. Colonoscopy showed diffuse moderate mucosal changes with congestion, erythema, friability, and loss of vascularity in the rectum extending in a contiguous fashion from 10cm to anal canal. Pathology reported nonspecific chronic inflammation with hyperplastic epithelial changes but negative for dysplasia or malignancy. He began oral mesalamine and mesalamine suppository therapy. With symptomatic improvement he was discharged home and was readmitted 3 days later with worsening hematochezia. He began intravenous steroids and his mesalamine therapy was changed to balsalazide. During the next 24 – 48 hours, he started having increased hematochezia with blood clots associated with increased rectal pain (pain scale 10/10). His vital signs were recorded as temperature 97.3F, blood pressure 58/32, heart rate 42, respiratory rate 9 and saturation of 86% on room air. His hemoglobin dropped from 9.6 to 7.7. He was resuscitated with IV fluids and PRBC transfusion. His blood pressure and heart rate normalized. At that point he was diagnosed with 5-ASA hypersensitivity. All his mesalamine products were discontinued and hydrocortisone suppositories began with continuation of his IV steroids. He improved and was discharged home with a steroid taper and daily hydrocortisone suppositories.
Discussion: 5-aminosalicylic acid (mesalamine) is currently the first line therapy for treatment of ulcerative proctitis. Although mesalamine hypersensitivity is not common, it is important to include it in the differential diagnoses of patients with pertinent inflammatory bowel disorders who present with worsening clinical symptoms after introduction to mesalamine or similar 5-aminosalicylic acid compounds.
