Human Orf Atypical Rash in an Urban Medical Practice
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Case Report Human orf Atypical rash in an urban medical practice Val E. Ginzburg MSc MD CCFP Iryna Liauchonak MD rf is one of the most widespread viral O diseases worldwide and is caused by EDITOR’S KEY POINTS Parapoxvirus.1 It can be transmitted to humans • Orf, which is well known to veterinarians and farmers, is an infection from goats, deer, sheep, and cattle. Orf (also caused by Parapoxvirus that mainly affects goats and sheep. Humans known as ecthyma contagiosum) can be trans- can contract orf through broken skin while handling infected animals mitted to people who have direct contact with or contaminated equipment. Urban physicians should be aware of orf while dealing with skin lesions and take into account patients’ cultural infected animals and it manifests as a ery- traditions, dietary customs, and migration to rural areas, as these factors thematous maculopapular lesion. Human put patients at risk of being exposed to the infection. orf is usually self-limiting and no specific treatment is needed. Complications are due • In the case of human orf, a lesion appears 3 to 7 days after contact with to misdiagnosis of this infection and, as a an infected animal and evolves slowly over the course of 4 to 8 weeks. result, it being overtreated, specifically by surgical debridement.2 • Human orf is a benign infection and its diagnosis can be based on clinical findings to avoid unnecessary expensive testing and invasive This article describes a case of a 67-year- treatment. The disease is self-limiting and clears without treatment old man who developed skin lesions on his within several weeks. Surgical debridement should be avoided because hands after taking care of goats and sheep it can lead to scarring and prolong the recovery period. The lesion on his farm in rural Ontario. Since he retired, should be kept clean with antiseptic solution to avoid a secondary he had spent most of his time on his farm bacterial infection. away from his home in Toronto, Ont; how- ever, he continued to see his family doctor POINTS DE REPÈRE DU RÉDACTEUR in Toronto. This case serves as a reminder to • L’ecthyma, bien connu des vétérinaires et des agriculteurs, est une urban physicians that it is important to con- infection causée par le parapoxvirus qui affecte principalement les sider zoonotic infection while dealing with chèvres et les moutons. Les humains peuvent contracter l’ecthyma skin lesions, as the rate of such infections par une lésion de la peau en manipulant des animaux infectés ou de has increased owing to a combination of l’équipement contaminé. Les médecins en milieu urbain devraient demographic changes, increased travel, agri- envisager l’ecthyma en présence de lésions de la peau et prendre cultural practices, and human invasion into en compte les traditions culturelles des patients, leurs coutumes animal habitats.3 alimentaires et leur migration vers les régions rurales, puisque ces facteurs exposent les patients au risque de contracter cette infection. Case • Dans le cas de l’ecthyma chez l’humain, une lésion apparaît de 3 à 7 A 67-year-old Canadian man present- jours après le contact avec un animal infecté et évolue lentement sur ed to the emergency department with une période de 4 à 8 semaines. a complaint of 2 painful blisters on the third and fourth digits of both hands that • L’ecthyma chez l’humain est une infection bénigne, et son diagnostic developed 7 days before the visit. He peut se fonder sur les constatations cliniques pour éviter des could not recall any injury or exposure to analyses coûteuses inutiles et des traitements invasifs. La maladie est a similar lesion. The blisters were tender spontanément résolutive et disparaît sans traitement après quelques and swollen and their centres became semaines. Il faudrait éviter le débridement chirurgical, parce qu’il ulcerated and crusted. The patient’s past pourrait causer des cicatrices et prolonger la période de guérison. Il medical history was unremarkable. He faut garder la lésion propre au moyen d’une solution antiseptique pour was not taking any medications and had éviter une infection bactérienne secondaire. no allergies. He mentioned that he was a retiree from Toronto but recently started This article has been peer reviewed. to raise goats and sheep to have organic Cet article a fait l’objet d’une révision par des pairs. Can Fam Physician 2017;63:769-71 cheese and meat. He also stated that he had not vaccinated his animals for the same reason. VOL 63: OCTOBER • OCTOBRE 2017 | Canadian Family Physician • Le Médecin de famille canadien 769 Case Report | Human orf On examination, he was afebrile and the rest of high-risk group for contracting the virus. A lesion his vital signs were within normal range. The 2 blis- appears 3 to 7 days after contact with an infected ani- tered nodules were similar in appearance, about mal and evolves slowly over the course of 4 to 8 weeks. 1.5 cm in diameter and feshy with ulcerated centres. It starts as a frm red painful papule that expands into There was no limitation of range of motion and no a broad, thickened 1- to 3-cm lesion. The centre of associated lymphangitis. One nodule on the right the lesion is red and is surrounded by a white, raised hand had mild surrounding erythema suggestive of a ring with erythematous periphery. The crusting occurs secondary bacterial infection. and resolves by 3 to 6 weeks with little to no scarring. The ulcerated centres of the blisters were biopsied, Recurrent lesions are possible, as the infection does and the tissue was sent for histology, bacterial cul- not confer immunity in humans.5 Figure 1 presents the ture, and sensitivity. The diagnosis of orf was made evolution of a typical milkers’ nodule6; milkers’ nodule based on the clinical fndings: the history of exposure is also caused by Parapoxvirus and has the same mani- to goats and sheep, as well as the appearance of the festation as orf. typical cutaneous lesions. Plain microscopy might detect viral disease. Defnitive The patient was advised to clean the lesions with diagnosis is possible through electron microscopy by antiseptic solution and keep them uncovered. He was demonstrating typical oval viral particles of Parapoxvirus. discharged with an over-the-counter anti-infammatory Polymerase chain reaction is more specifc for identify- medication for analgesia and 500 mg of cephalexin ing DNA of the virus in the specimen regardless of the orally 4 times daily for 7 days for secondary cellulitis. stage of the disease.7 Follow-up 3 days later showed no progression of the No treatment, including surgical debridement, is lesions. The secondary erythema had resolved. One necessary, as the disease is self-limiting. The com- month later the lesions had completely resolved without mon approach to treat ulcers with surgical debride- residual scarring. ment is considered unnecessary in cases of human orf Histologic fndings with light microscopy demon- because it might cause scarring and prolong the recov- strated acanthotic squamous epithelium with diffuse ery period. The lesion should be kept clean with anti- necrosis of the epidermis and large areas of hemor- septic solution to avoid a secondary bacterial infection. rhage and crusting with acute infammatory exudate. Immunocompromised patients need to be treated with The underlying small fragment of papillary dermis topical imiquimod or cidofovir. In the case of a second- showed fbrin deposition and crushed infammatory ary bacterial infection that might present with erythema, cells. The features described above suggested orf (or purulent secretion, lymphadenitis, or systemic symp- milkers’ nodules, which is an alternative name for toms, antibiotics would be indicated.2 human orf). No viral inclusions were identifed. A viral Differential diagnosis of orf includes several diseases infection could be confrmed by either virologic stud- such as cutaneous anthrax, pyoderma gangrenosum, ies or by ultrastructure examination of the skin biopsy. and herpetic whitlow.8 Both human orf and cutaneous No further investigations were done, as the nature anthrax can be acquired from sheep and goats. Thus, of the disease was clear and the follow-up visit con- history alone cannot be helpful in establishing defnitive firmed the self-limiting condition. diagnosis. Cutaneous anthrax lesions are fast spreading and ulcerating, and they quickly respond to an appropri- Discussion ate antibiotic. If diagnosis remains unclear, then elec- Orf is an infection caused by Parapoxvirus that mainly tron microscopy can confrm a diagnosis of Parapoxvirus affects goats and sheep. In animals the lesions are local- infection; only polymerase chain reaction can defnitely ized on lips, nostrils, udders, and toes. The disease is identify a viral infection such as orf. Pyoderma gan- self-limiting and clears without treatment within 3 to 4 grenosum is most common in patients with underly- weeks. Animals that recover from the infection develop ing systemic disease. It starts as a vesicle or papule on lifelong immunity. A vaccine for animals against orf is the trunk or limbs, which then enlarges and ulcerates. available and provides good protection.4 Herpetic whitlow manifests as a vesicular rash on fn- There are limited data on the incidence of human gers, often after contact with a vesicle caused by the orf, as most orf infections go unreported owing to its herpes simplex virus. self-limiting nature. Also, those who are infected are often familiar with the disease and do not seek Conclusion medical attention. Orf is a viral disease that is well known to farmers Humans get infected while handling animals, car- and veterinarians. Urban physicians should be aware casses, or contaminated equipment by direct inoculation of it while dealing with skin rashes and lesions and through cuts or abrasions.