[The Orf nodule].

Human Orf disease is an exceptional dermatologic benign condition, due to a Parapox virus. In sheep and goats this infection is termed "Ecthyma Contagiosum". Human beings are contaminated from infected animals. We report three cases of Orf disease in the same family. Typical viral particles have been identified in the skin of one of these patients by electronic microscopy but cultures failed to recover the pathogen. A complete study of the literature allows us to review current knowledge on this disease with which practitioners are unfamiliar.