Ecthyma contagiosum (orf) - Report of a human case from the United Arab Emirates and review of the literature

Background: Ecthyma contagiosum (orf) is caused by an epitheliotropic parapox virus. It is a zoonosis usually transmitted to humans from affected sheep or goat through direct contact or contaminated fomites. Methods: We report a 36-year-old patient with multiple skin lesions on his left hand, first observed 5 days before admission followed by red streaks on the forearm and an erythema on the upper arm 1 day prior to admission. The patient reported that he was working on a sheep farm. Results: Histopathologic examination showed evidence of a viral infection. Subsequent transmission electron microscopy showed typical parapox virus particles, predominantly in the scaled-off layers of degenerated keratinocytes and monocytes. The results were verified and specified by two newly established polymerase chain reaction (PCR) assays and subsequent sequencing of the amplicons: one broadly reacting 'general parapox virus PCR', and one assay which allows - following sequencing - discrimination between individual orf virus strains. Conclusion: Despite the multiplicity of the lesions, there was a significant improvement after 2 weeks of treatment. Sequencing showed the uniqueness of this virus compared with previously published strains from other countries.