P605 Presentation and progression of childhood-onset inflammatory bowel disease in northern Stockholm County

Epidemiology S321 29.6 [21.0 43.1] years).Erythema nodosum was diagnosed in 71/160 (44.4%), pyoderma gangrenosum in 9 (5.6%), psoriasis in 36 (22.5%),Sweet's syndrome in 2 (1.3%), hydradenitis suppurativa in 3 (1.9%) and aphthous stomatitis in 54 (33.8%).In 92/160 (57.5%) an arthritic and in 18/160 (11.3%) an ophthalmologic EIM was also present.CD was located in the terminal ileum in 31.4% while 21.6% had colitis, 47.1% ileocolitis, 15.7% upper GI and 20.6% perianal involvement, 77.5% an inflammatory, 18.8% a stricturing and 5% a penetrating behaviour.In ulcerative colitis patients, 14.9% had proctitis, 19.1% left-sided and 66% extensive colitis according to Montreal classification.Fifty-four out of 158 (34.2%) developed a DM before IBD diagnosis (median [IQR] duration of 1st DM until IBD diagnosis: 5.1 [0.8 14.6] years).No correlation was found with gender and disease type.DMs presented more frequently in active IBD (78%, p < 0.0001) and regressed when IBD turned into remission (p = 0.012, mainly erythema nodosum and psoriasis), in patients with ileo-anal pouch anastomosis (p = 0.015) and when an arthritic EIM existed (p < 0.0001, mainly erythema nodosum and psoriasis).In particular, psoriasis was more frequent between smokers (p = 0.033), anaemic patients and those who had tonsillectomy (p = 0.045), pyoderma gangrenosum in CD colitis (p = 0.009) and aphthous stomatitis in CD ileocolitis (p = 0.031) and when there was a change in IBD behaviour (p = 0.03).Conclusions: DMs represent more than one third of EIMs in our population of IBD patients.They are frequently accompanied by other EIMs.IBD activity but not gender and disease type or classification was associated with DMs appearance.