Inflammatory bowel disease (IBD) is associated with extra-intestinal manifestations, the most common of which is arthralgia/arthritis. 4.1- 15% of patients with inflammatory bowel disease have arthritis¹. There has been little to no published research indicating how frequently arthritis is the presenting manifestation of IBD. We performed a case-control study to investigate whether differences exist in initial laboratory values and body measurements in patients with arthritis who are ultimately diagnosed with IBD-associated arthritis compared to patients with juvenile idiopathic arthritis (JIA) without IBD.

Methods:

A retrospective review of children who presented to University Hospitals Rainbow Babies and Children’s Hospital (UH RB&C) pediatric rheumatology clinic between 2010 and 2015 was performed. Children were identified who presented with arthritis without overt gastrointestinal symptoms and who were subsequently diagnosed with IBD. Age and gender matched controls were identified from children with oligoarticular or polyarticular JIA who were seen in the pediatric rheumatology clinic during the same time period. Controls and cases were matched at a 2:1 ratio. Body morphometrics (weight and height) and laboratory results (hemoglobin, platelet count, erythrocyte sedimentation rate, C-reactive protein, and serum albumin) were obtained at their first pediatric rheumatology visit. In all cases, the diagnosis of IBD was confirmed by endoscopy/colonoscopy with intestinal biopsy. Statistical analysis was performed using R software. The univariate analyses were obtained for all variables and if significant (p-value < 0.05) these variables were then included in the logistic regression.

Results:

We identified 12 patients who presented with arthritis and were subsequently diagnosed with IBD. Using the univariate analysis, patients with IBD associated arthritis had significantly lower weight, hemoglobin, albumin and total protein as well as higher CRP and ESR values. Compared to age and gender matched controls (n = 24), patients with IBD-associated arthritis were significantly more likely to have a lower weight percentile and lower albumin levels as compared to patients with JIA without IBD using odds ratios (OR=0.54, 0.023). Performing the multi-variate analysis showed that patients with IBD associated arthritis had significantly elevated CRP and lower weight (p-value= 0.034).

Conclusion:

These data suggest that in patients presenting with arthritis with elevated C-reactive protein in association with lower weight percentile (less than the 25^th percentile), IBD should be excluded as the cause for arthritis.