To investigate clinical manifestations, histopathological features and treatment of ulcerative colitis (UC) complicated by pyoderma gangrenosum (PG) .

Data on clinical manifestations, auxiliary examination findings, treatment and prognosis were collected from 8 inpatients with UC complicated by PG in Peking Union Medical College Hospital between July 2009 and July 2016, and analyzed retrospectively.

Of the 8 cases, 5 were male, and 3 were female. The average age of onset was 30.6 years and 35.1 years in males and females respectively. All the patients developed intestinal symptoms of UC before the onset of PG with an average time interval of 5 years. Moreover, all the patients had active total colonic type UC at the onset of PG, including 6 with moderately active UC and 2 with mildly active UC. PG manifested as painful ulcers in 8 patients, and affected lower limbs in 7 patients. Histopathological examination of skin lesions showed typical characteristics of vasculitis in 5 patients. Five patients were complicated by arthralgia. All the patients were treated with glucocorticoids and 5-aminosalicylic acid agents as the basic therapy, 3 patients received extra treatment with immuno-suppressive agents or minocycline, and 2 with infliximab.

PG is a severe skin manifestation of UC, commonly occurs in patients with total colonic type UC in the active stage, and mostly affects the lower limbs, with typical histopathological features of vasculitis.

Pyoderma gangrenosum; Colitis, ulcerative; Disease attributes; Treatment outcome; Inflammatory bowel disease