Should extraintestinal manifestations (EIMs) be part of disease activity assessment in ulcerative colitis?

The Simple Clinical Colitis Index (SCCAI) is a clinical index specific to ulcerative colitis (UC). The SCCAI is comprised of six descriptors: daytime bowel frequency, nocturnal bowel frequency, urgency, bleeding, general well-being and EIMs. Four out of a total of 19 points are allocated to EIMs: arthritis, uveitis, erythema nodosum (EN), pyoderma gangrenosum (PG). It is increasingly clear that the major determinant of EIMs are genetic rather than due to underlying disease activity. Physicians question whether the presence or absence of EIMs have any place in an index designed to capture disease activity.