Comparison of demographic and clinical characteristics of anti-TNF-treated patients with IBD with and without anti-TNF-induced psoriasiform skin lesions (univariate analysis)
| Anti-TNF-treated patients with IBD without psoriasiform skin lesions (n=413) | Anti-TNF-treated patients with IBD with psoriasiform skin lesions (n=21) | p Value | OR | 95% CI | |
|---|---|---|---|---|---|
| Median age (years), n=434 | 38.0 | 31.0 | 0.48 | 0.99 | 0.95 to 1.02 |
| IQR | 28.0–47.0 | 28.0–44.0 | |||
| Gender (% women), n=433 | 201 (48.8%) | 11 (52.4%) | 0.75 | 1.15 | 0.48 to 2.83 |
| Crohn's disease, n=434 | 312 (75.5%) | 19 (90.5%) | 0.14 | 3.08 | 0.87 to 19.51 |
| Ulcerative colitis, n=434 | 101 (24.5%) | 2 (9.5%) | 0.14 | 0.33 | 0.05 to 1.15 |
| Stenosis, n=414 | 227 (57.8%) | 14 (66.7%) | 0.42 | 1.46 | 0.59 to 3.93 |
| Fistulas, n=411 | 175 (44.9%) | 13 (61.9%) | 0.13 | 2.00 | 0.82 to 5.15 |
| Median IBD duration (years), n=431 | 10.0 | 7.0 | 0.049 | 0.94 | 0.87 to 0.99 |
| IQR | 5.0–18.0 | 3.0–11.0 | |||
| Median BMI (kg/m2), n=384 | 22.7 | 24.9 | 0.007 | 1.13 | 1.03 to 1.24 |
| IQR | 20.0–25.5 | 23.4–27.3 | |||
| History of smoking or active smoking, n=408 | 165 (42.6%) | 16 (76.2%) | 0.005 | 4.31 | 1.65 to 13.38 |
| Treatment with infliximab, n=434 | 387 (93.7%) | 21 (100.0%) | 0.36 | N/A* | N/A* |
| Treatment with adalimumab, n=425 | 130 (32.2%) | 11 (52.4) | 0.06 | 2.32 | 0.95 to 5.70 |
| IQR | 3.0–13.0 | 5.0–13.25 | |||
| Treatment with azathioprine or 6-mercaptopurine, n=426 | 377 (93.1%) | 19 (90.5%) | 0.65 | 0.71 | 0.19 to 4.57 |
p Values, OR and 95% CIs are given for the comparison of each demographic and clinical variable between anti-TNF-treated patients with psoriatic skin lesions (n=21) and without psoriatic skin lesions (n=413). The number of patients with detailed information on the respective demographic or clinical characteristic is given for each variable as ‘n=…’.
*Since all patients in the group with anti-TNF-induced skin lesions received infliximab, no meaningful OR can be calculated due to the division by zero. There were statistically significant differences in the prevalences of smokers, BMI and disease duration between the two study groups; these three variables were confirmed as predictors of anti-TNF-induced psoriasiform skin lesions by multiple regression analysis.
BMI, body mass index; IBD, inflammatory bowel diseases; TNF, tumour necrosis factor.