The observation belongs to a 22 year-old man, who presented a lesion in the index finger of the right hand, with a nodular induration, which later turned into an ulcer and was cured in a month and a half. In the beginning it was painless, becoming painful after the third week. He was given a treatment of a simple topical application. The histopathologic study showed the existence of an inflammatory chronic process with epidermic alterations characterised by the presence of necrosis and vesicles (reticular degeneration). There was also a significant presence of mural necrosis of vessels of the papillar dermis and subpapillar plexus, with recent partial mural thrombosis, that authors consider of importance in the pathogenic of the process. Comments are made about the evolution of the illness in man and in caprines and ovines. On enclose the histopathologic study of a biopsy of lip, extracted from a sheep affected by this illness. This showed a microscopic picture similar to the one described above.