A Case of Milker's Nodule

Milker's nodule is a harmless skin lesion that's caused by the paravaccinia virus (also called pseudocowpox virus), which is a member of the genus Parapoxviridae. It occurs worldwide, but it is prevalent only in individuals who are in close contact with cattle. We report here on a woman who presented with a dusky purpuric center surrounded by a white or gray ring and an outer red halo on the back of the right hand. Histologically, intracytoplasmic inclusion bodies were evident in the upper epidermis, and these revealed cylindrical virus particles on electron microscopy. Parapoxvirus was identified by polymerase chain reaction with using pan-parapoxvirus primer 1 (PPP-1) and PPP-4.