A 15-year-old male presented with about two weeks history for a solitary pustular plaque on his finger. There was no lymphadenopathy and he had not any significant medical problem. 

What is your diagnosis? 

Diagnosis: Orf

Orf is a viral infection which is widespread in sheep and goats and humans are infected by direct inoculation of infected animal material. It is characterized by a reddish papule which enlarges to form a hemorrhagic pustule or bulla. It is usually surrounded by a grayish- white or violaceous ring which is in turn encircled by a zone of erythema.

This patient had a close contact with a sheep during a sacrificial ceremony and got this lesion a few days after contact.

 Omid Zargari, MD