Reaginic hypersensitivity in ulcerative colitis.

Reaginic hypersensitivity in ulcerative colitis has been investigated in respect of a hypersensitivity to the cow's milk proteins and the frequency of atopic asthma, hay fever, and eczema. Intradermal tests were frequently positive, especially to casein, but the results did not differ from those found in healthy individuals and in groups of patients with Crohn's disease, hypolactasia, and the irritable colon syndrome. No circulating IgE-specific antibodies to the milk proteins were found. An increased frequency of atopic diseases was found in patients suffering from ulcerative colitis (15.7%) and Crohn's disease (13.3%) compared with the findings in a control group (1.2%). It is concluded that, if an allergy to milk proteins is a factor in the pathogenesis of ulcerative colitis, it is not mediated by reaginic antibodies. It is possible, however, that the frequent occurrence of atopy indicates a susceptibility to develop reaginic responses even though this mechanism does not apply to the milk proteins.