Milker's nodules. Pathogenesis, tissue culture, electron microscopy, and calf inoculation

We report the occurence of milker's nodules in nine patients. In man, the disease goes through maculopapular, target, acute weeping, nodular, papillo-matous, and regressive stages. Papular and papillomatous stages were noted following vaccination of a calf with material prepared from a human lesion. A viral agent was isolated in cultures of bovine kidney cells and human skin fibroblast cells. Cytoplasmic inclusions were frequently seen in the infected bovine kidney cells. Electron microscopy revealed viroplasm, partially encapsulated viroplasm, encapsulated viroplasm, and oval particles with spires around the outside.