Risk factors for intolerance of oral 5-aminosalicylic acid preparations in pediatric ulcerative colitis.

BACKGROUND

No previous study of Japanese children with ulcerative colitis (UC) has reported the risk factors for intolerance of 5-aminosalicylic acid (5-ASA). We aimed to identify risk factors for intolerance of oral 5-ASA preparations in pediatric UC.

METHODS

Patients with childhood-onset UC who were seen at our hospital between November 2003 and March 2020 were investigated. Intolerance of 5-ASA was defined as having clinical symptoms (pyrexia, abdominal pain, diarrhea, bloody stool) that worsened after starting oral administration of 5-ASA and improved after discontinuation of 5-ASA. Patient sex, age, body size, laboratory data, pediatric UC activity index scores, and colonoscopy-based determinations of the extent and severity of the affected lesion at initiation of 5-ASA of intolerant and tolerant groups were compared.

RESULTS

Fifteen patients were in the intolerant group, and 37 were in the tolerant group. The leukocyte count, C-reactive protein level, and erythrocyte sedimentation rate were significantly higher in the intolerant group than the tolerant group; the albumin level in the intolerant group was significantly lower. All intolerant patients and 68% of tolerant patients had pancolitis (Paris classification E4). Patients with a large, affected area (Paris classifications E3 and E4) more frequently had intolerance to 5-ASA than patients with a small lesion. The cumulative Mayo endoscopic subscore (cMES), which is the sum of MES scores for six regions of the large intestine, was significantly higher in the intolerant group.

CONCLUSIONS

Pediatric UC patients with more intense inflammation and a large lesion could have an increased risk of intolerance for 5-ASA.