Orf. A case report with histologic, electron microscopic, and immunoperoxidase studies

Orf is an occupational skin disease acquired through contact with infected animals. In humans, orf is usually a self-limited disease that resolves spontaneously within four to 24 weeks. We report a case with multiple lesions of orf, acquired by contact with a wild sheep. The patient was temporarily immunosuppressed by a concomitant viral hepatitis. We reviewed the histologic and electron microscopic findings. Also, we attempted to stain the Parapoxvirus in the skin of the patient, using the immunoperoxidase technique. The antiserum was obtained from sheep immunized against orf. We used lesional skin from sheep infected with orf as a positive control. The negative results of this technique in the patient's skin indicated that parapoxvirus infecting wild sheep is antigenically different from that causing the disease in domestic animals.