A 26-year-old woman who emigrated to the United States 5 years ago from the Sudan was admitted to a hospital with pre-eclampsia. An incidental finding on admission was a painless rounded, raised lesion on the palm of her right hand. There was no surrounding erythema or edema. This lesion had been present for two weeks.
She had not left the United States since emigrating from Sudan, and had had no such lesions before.
Through an interpreter, it was determined that three weeks previously she had obtained a sheep's head from a halal butcher to be used in cooking. While preparing the head she accidently cut her hand with a spicule of bone from the front part of the sheep's face. She subsequently developed the described lesion.
The most likely cause of this lesion would be:
0%Anthrax
0%Brucella
0%Mycobacterium ulcerans
0%Orf
ORF is a poxvirus (specifically a parapoxvirus) that causes painless lesions at inoculation sites about 14-21 days after inoculation and which ultimately resolve spontaneously over 4-8 weeks. It does not typically cause systemic symptoms or disseminate except in unusual cases in immunosuppressed hosts. There is no therapy.
The patient has a painless ulcerated nodule. The differential might include anthrax, leishmania, or Buruli ulcer: patients are not necessarily systemically ill with any of these entities (with cutaneous anthrax, however, systemic manifestations may develop). This woman had been in the United States for 5 years, making Leishmania and anthrax unlikely. Anthrax is seen primarily in the United States in bison, not domestic animals. Buruli ulcers, due to M. ulcerans, are acquired in Africa, not the United States.
Orf is common in herds of goats and sheep: contact with oral lesions of animals, or with milking them, can lead to this type of lesion. Presumably this woman had contact with an oral lesion in the sheep head and the virus was then inoculated into her skin by the minor trauma.
Similar cases can occur with goats, deer, or with elk. See the lesion in the goat oropharynx below.