Cutaneous vasculitis in ulcerative colitis mimicking Henoch-Schönlein purpura.

To the best of our knowledge, no cases of ulcerative colitis (UC) mimicking Henoch-Schönlein purpura (HSP) have been reported so far. During a 28-year period 5635 patients were followed up at our Pediatric Rheumatology Unit and 357 had HSP according to the European League Against Rheumatism, the Paediatric Rheumatology International Trials Organisation and the Paediatric Rheumatology European Society validated classification criteria. At the same period, 148 patients with IBD according to the European Society for Paediatric Gastroenterology, Hepatology and Nutrition criteria were followed up at the Pediatric Gastroenterology Unit in our University Hospital. Only two of them had vasculitis, as an extra intestinal manifestation of UC mimicking HSP, and fulfilled both disease criteria. A 2-year old girl had bloody diarrhoea, severe abdominal pain, arthritis in ankles, petechiae and palpable purpura not related to thrombocytopenia in lower limbs. A 5-year old boy had bloody diarrhoea, palpable purpura in buttocks, lower limbs, penis and scrotum associated with arthritis in knees, orchitis in right testicle and periarticular swelling in hands and feet. Their ileocolonoscopy showed diffuse mucosal erythema, oedema, friability and multiple irregular ulcers, and histopathological examination of colonic specimen revealed diffuse chronic mucosal inflammation, crypt distortion and crypt abscesses suggesting ulcerative colitis. There were no signs of intestinal vasculitis in both cases. In conclusion, this is the first study in a paediatric population that evidenced palpable purpura associated with UC mimicking HSP.