Treatment of Orf (Ecthyma Contagiosum)
Orf is a self-limiting viral infection that typically resolves spontaneously within 6-8 weeks without specific treatment. Supportive care with local antiseptics is the mainstay of therapy to prevent secondary bacterial infections.
Disease Overview
- Orf (contagious ecthyma) is a zoonotic viral infection caused by a parapoxvirus that primarily affects sheep and goats 1, 2
- Humans contract the infection through direct contact with infected animals or fomites, making it an occupational hazard for farmers, shepherds, veterinarians, and butchers 2
- The infection typically presents as painful nodules or plaques on the hands and fingers after an incubation period of 3-7 days 2
Clinical Presentation
- Lesions evolve through six clinical stages over approximately 6-8 weeks:
- Maculopapular stage (days 1-7): erythematous macules or papules 2
- Target stage (days 7-14): lesions with necrotic center and red outer halo 2
- Acute stage (days 14-21): weeping nodules 2
- Regenerative stage (days 21-28): drying of nodules 2
- Papilloma stage (days 28-35): papilloma-like appearance with dry crust 2
- Regression stage (after 35 days): spontaneous healing 2
- Complications may include lymphangitis, lymphadenopathy, fever, malaise, and occasionally erythema multiforme 2
Diagnosis
- Diagnosis is primarily clinical, based on characteristic appearance of lesions and history of contact with infected animals 2
- Differential diagnoses include milker's nodule, cutaneous anthrax, atypical mycobacterial infection, cutaneous leishmaniasis, and fungal infections 2
Treatment Approach
First-line Treatment
- Apply local antiseptic solutions to prevent secondary bacterial infection 2, 3
- The infection is self-limiting and typically resolves without specific treatment within 6-8 weeks 2
- Supportive care focuses on preventing complications and managing symptoms 1, 2
For Complicated Cases
- For painful lesions, symptomatic relief may be provided 2
- In cases with secondary bacterial infection, topical antibiotics such as 2% fusidic acid cream may be beneficial 3
- For complicated cases (erythema multiforme, giant lesions, or persistent infection), topical imiquimod cream has shown rapid improvement 4
What to Avoid
- Surgical debridement should be avoided as it may prolong recovery time 2
- Cryotherapy has been reported but lacks supporting evidence 2
Prevention
- Wear nonporous gloves when handling sheep or goats 2
- Wash hands thoroughly after handling animals 2
- Isolate infected animals to prevent further transmission 2
- Vaccination of animals (though controversial due to short-term immunity) may help control outbreaks 5
Special Considerations
- Immunocompromised patients may develop giant, persistent, or recurrent lesions requiring more aggressive management 4
- Zoonotic transmission to humans from infected animals is common, emphasizing the importance of preventive measures 5
- The disease has significant economic impact on livestock farming despite its generally benign nature in humans 5