Rash in a slaughterhouse worker

A 32-year-old man presented to the emergency department with a new rash on his left hand that has a clear discharge. He was employed at a livestock slaughterhouse and did not wear gloves when handling animals. The most common animals he was in contact with were sheep and goats. The rash was only in one location, between his third and fourth digit on his left hand (Figures 1 and 2) and worsened over the previous 4 days. The blister is approximately 1 cm × 1 cm × 1 cm and tender to touch. He denied any fevers, chills, or additional rashes. Due to the uniqueness of the patient's profession, dermatology was consulted and a shave biopsy was performed.

The patient was ultimately diagnosed with Orf virus based on clinical presentation alone. Tissue biopsy showed epidermal hyperplasia with vacuolated cytoplasm and eosinophilic inclusion bodies in upper epidermal keratinocytes, ulceration, and mixed inflammatory infiltrate, which aligned with the clinical diagnosis of Orf. Orf is caused by the Parapoxvirus and is often self-limiting, lasting around 4–6 weeks. It is found in people who have direct contact with animals, most commonly farms. Treatment is mainly supportive, cleaning the wound with soap and water, and keeping the wound dry and covered with a bandage. It is important to keep zoonotic diseases on the differential of rash.