Clinical features and course of ulcerative colitis diagnosed in asymptomatic subjects

Although some ulcerative colitis (UC) patients are diagnosed when they do not have any UC-related symptoms, clinical features and prognosis of UC diagnosed in asymptomatic patients remain unclear.

Data for UC patients who were asymptomatic at diagnosis were retrospectively reviewed from the IBD database of the Asan Medical Center. The clinical characteristics and prognosis of those patients were analyzed and compared with matched (1:4) symptomatic UC patients.

Only nineteen asymptomatic UC patients (1.1%) were identified from 1665 UC patients. The proportion of males was 78.9% (n=15), and their median age at diagnosis was 48 years (range, 34-71 years). At diagnosis, proctitis was noted in 11 patients (57.9%), left-sided colitis in 4 (21.1%), extensive colitis in 0 (0%), and atypical distribution in 4 (21.1%). The 5-year cumulative probability of symptom development was 68.5% (95% confidence interval [CI], 62.8%-74.2%). After UC diagnosis, oral 5-aminisalicylic acid (ASA) and topical 5-ASA were used in 14 (73.7%) and 16 (84.2%) patients, respectively. During follow-up (3.7-year median for asymptomatic patients versus 3.7-year median for symptomatic patients; P=0.961), the 5-year cumulative probability of corticosteroids (23.7% versus 57.1%; P=0.022) and azathioprine (0% versus 24.7%; P=0.003) use was higher in symptomatic patients than in asymptomatic patients.

The frequency of asymptomatic UC patients was 1.1% in our UC patient cohort. A majority of these patients became symptomatic during follow-up. Asymptomatic UC patients at diagnosis appear to have a better prognosis than symptomatic UC patients.