Orf lesions are usually seen on the fingers or hands of an individual who has touched the infected animal (e.g. bottle feeding or shearing the animal). Occasionally the orf lesions can also be seen on the face or other parts of the body that may have been in contact with the infected animal.
The orf lesion evolves through distinctive stages and can be painful. A red bump develops about 1 week after contact with the virus. An infected person may experience mild fever and malaise for the first few days. Red streaks (infected lymph channels) may be visible on the affected limb and the nearby lymph glands can be enlarged.
The red bump may grow from 2 to 5 cm and develop rings of white and red around a central red area, after which it usually becomes a blood/pus/fluid filled blister which can weep and bleed easily. A dry crust usually develops on top and the lesion then starts to take on a warty appearance. The lesion will heal without treatment after 4 to 6 weeks, usually without scarring. The infection does not usually spread from person to person.