RESUMO
A group of 152 patients with a verified diagnosis of ulcerative colitis (including haemorrhagic proctitis) was compared with a control group with an identical sex ratio, age, and social class distribution. All patients attended an ulcerative colitis out-patient clinic, and had been examined and followed by the members of the team. By the use of questionnaires information was gathered concerning familial incidence of the following diseases: ulcerative colitis, regional ileitis, cancer of the colon and rectum, allergic diseases of the immediate type (bronchial asthma, urticaria, allergic rhinitis, and atopic dermatitis), diseases presumably caused by delayed hypersensitivity (erythema nodosum), or auto-allergy (rheumatoid arthritis and ankylosing spondylarthritis). Eight families with more than one case of ulcerative colitis were found in the patient group (5.3 per cent) compared to only one case in the control group (0.7 per cent). This difference is significant. No cases of regional ileitis were observed, either in the patient group or in the control group. Cancer of the colon and rectum did not occur significantly more often among the relatives of patients with ulcerative colitis. The preponderance of urticaria and allergic rhinitis in the ulcerative colitis families and the even distribution of rheumatoid arthritis, erythema nodosum, and ankylosing spondylarthritis in the two groups compared tends to support the hypothesis that an allergic pathogenesis of ulcerative colitis is of the immediate type.