Milker's nodule (paravaccinia) is a skin infection caused by parapoxvirus which is morphologically similar to Orf virus. The virus produces mild localized lesions on the udders of cows as well as ulcers in the mouths of calves. Dairy farmers or veterinarians who examine the mouths of animals acquire the virus by direct contact with infected lesions or via contaminated fomites. Humans-to-human transmission has not been documented. Aftern an incubation period of 5-6 days, the patients develop 2 to 5 small red papules on fingers, hand, and sometimes face. Over the next 7-10 days, the lesions grow into red-bluish, slightly tender blisters or nodules. The center of the lesion may be depressed and show crusting. The overlying epidermis is tense and shiny at first and eventually becomes opaque and grey. Secondary bacterial infection may occur. The patient may develop lymphadenitis and lymphangitis. There are no systemic manifestations. Some patients develop a papulovesicular eruption (erythema multiforme) on upper and lower limbs which disappears in 1-2 weeks. The lesions resolve spontaneously without scarring in 4-6 weeks.