Orf parapoxvirus infection from a cat scratch.

A 53-year-old woman presented with an enlarging, tender, ulcerated nodule on her dorsal hand after being scratched by a stray kitten. Histology was consistent with orf parapoxvirus infection. The lesion resolved without scarring after several weeks of treatment with imiquimod 5 percent cream. Orf is a zoonosis transmitted to humans from sheep and goats by direct contact or by fomites. Transmission by cat scratch has not been previously described in the literature.