MILKERS' nodules in man is a virus disease of the skin acquired, in most instances, from milking cows who are infected with natural (not vaccinia or genuine) cowpox. Natural cowpox is a virus disease of the teats and the udders of milch cows and is common among dairy cows in Iowa and probably throughout the United States. Becker1 was the first to report milkers' nodules in this country; he described four cases in residents of northern Minnesota and Wisconsin. After hearing Becker's presentation, Beck2 reported three cases from Delaware, and a few years later Green3 reported one case from Louisiana. Green stated that he had seen many cases of the disease and had recognized it as an occupational disease of milkers. Hester and associates4 studied an epidemic in a dairy herd in Illinois; they saw one case of milkers' nodules and heard of several others.