Cutaneous Responses to Cholera Skin Toxin in Man. I. Responses in Unimmunized American Males

Abstract

Graded doses of the vascular-permeability factor, or skin toxin, of Vibrio cholerae and of heated control material were injected intracutaneously in a group of 93 normal males from the United States, who had no history of exposure to cholera antigens. In all 93 subjects, 0.025 limit-of-blueing dose of unheated toxin elicited readily palpable, firm swellings which reached maximal diameters of 5–14 mm on the third day. The same dose of heated toxin caused comparable skin response in only one out of 93 subjects. In the doses used, cholera skin toxin did not produce necrosis, hemorrhage, ulceration, or systemic reactions in any of the subjects. The lesions of the skin disappeared slowly but completely over a period of six months. Since circulating antitoxin to permeability factor suppresses the response to skin toxin in animals, the present study suggests that a skin test with cholera toxin in man could be safely used as an indicator of previous immunologic experience with cholera toxin and perhaps as a test for susceptibility to cholera.