Extraintestinal Manifestations of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is primarily a disease of the digestive tract system, though it may affect other organ systems outside of the intestines. Extraintestinal manifestations (EIMs) can occur in up to one third of patients with Crohn's disease or ulcerative colitis. The most common EIMs involve dermatologic and musculoskeletal manifestations. EIMs may either parallel intestinal inflammation or be completely independent of disease activity. Physicians should be aware of EIMs and think systematically when evaluating patients with IBD, as nearly every organ can be involved, and a multidisciplinary treatment approach should be undertaken to improve outcomes and quality of life.

The Risk of Later Diagnosis of Inflammatory Bowel Disease in Patients With Dermatological Disorders Associated With Inflammatory Bowel Disease

BACKGROUND

Dermatological conditions such as erythema nodosum (EN), pyoderma gangrenosum, Sweet's syndrome, and aphthous stomatitis can occur with inflammatory bowel disease (IBD) and are considered dermatological extraintestinal manifestations (D-EIMs). Rarely, they may precede IBD. Other common conditions such as psoriasis have also been associated with IBD. This study examined the risk of a subsequent IBD diagnosis in patients presenting with a D-EIM.

METHODS

A retrospective cohort study compared patients with D-EIMs and age-/sex-matched patients without D-EIMs. Hazard ratios (HRs) were adjusted for age, sex, body mass index, deprivation, comorbidity, smoking, loperamide use, anemia, and lower gastrointestinal symptoms. Logistic regression was used to produce a prediction model for the diagnosis of IBD within 3 years of EN diagnosis.

RESULTS

We matched 7447 patients with D-EIMs (74% female; median age 38 years (interquartile ratio [IQR], 24-65 years) to 29,297 patients without D-EIMs. We observed 131 (1.8%) subsequent IBD diagnoses in patients with D-EIMs compared with 65 (0.2%) in those without D-EIMs. Median time to IBD diagnosis was 205 days (IQR, 44-661 days) in those with D-EIMs and 1594 days (IQR, 693-2841 days) in those without D-EIMs. The adjusted HR for a later diagnosis of IBD was 6.16 (95% confidence interval [CI], 4.53-8.37; P < 0.001), for ulcerative colitis the HR was 3.30 (95% CI, 1.98-5.53; P < 0.001), and for Crohn's disease the HR was 8.54 (95% CI, 5.74-12.70; P < 0.001). Patients with psoriasis had a 34% increased risk of a subsequent IBD diagnosis compared with the matched control patients (HR, 1.34; 95% CI, 1.20-1.51; P < 0.001). We included 4043 patients with an incident EN diagnosis in the prediction model cohort, with 87 patients (2.2%) diagnosed with IBD within 3 years. The model had a bias-corrected c-statistic of 0.82 (95% CI, 0.78-0.86).

CONCLUSIONS

Patients with D-EIMs have a 6-fold increased risk of a later diagnosis of IBD. Younger age, smoking, low body mass index, anemia, and lower gastrointestinal symptoms were associated with an increased risk of diagnosis of IBD within 3 years in patients with EN.