A solitary finger nodule with a papulovesicular hands and feet eruption: a complicated human Orf virus infection

Introduction: and aims Orf virus (ORFV) is the pathogen responsible for Orf, a zoonotic viral infection that can be spread to humans from sheep and goat. Here, we present a case report of an ORFV infection complicated by an immune-related reaction to raise awareness of this under-recognized disease. Case report A 51-year-old woman presented with a 1-week history of a single asymptomatic swelling nodule with grey necrotic centre and red outer halo on her index finger. At physical examination, a pruritic papulovesicular eruption was also assessed on her hands and feet. Laboratory tests were within normal ranges and no past medical history was reported. She reported a recent contact with a goat which had a similar nodule in her mouth. The lesions biopsies were compatible with Orf virus infection complicated by erythema multiforme. The lesions spontaneously resolved within the next 2 weeks. Conclusions: Clinicians should be aware of the primary presentation and the potential complications that may occur in case of Orf virus infection. Erythema multiforme is the most frequently reported Orf-induced immunological diseases and, although histopathological examination might help, generally, clinical and epidemiological characteristics are enough to achieve a prompt diagnosis. Both primary and secondary lesions generally auto-resolve without needing any unnecessary overtreatment.