Clinical and histopathological presentation and successful treatment with ciclosporin for canine sarcoidosis: a case report

Background Sarcoidosis is a granulomatous disease histologically characterized by naked granulomas in various mammals. Canine sarcoidosis is a rare disease which can cause nonpruritic papule, plaques and nodules on the trunk, neck, face and ear; it is usually treated with corticosteroids. To date, there are no published reports on alternatives to corticosteroids treatment. Objectives To report a case of canine cutaneous sarcoidosis successfully treated with oral ciclosporin. Animal An 11‐year‐old beagle dog was presented with multiple pleomorphic plaques on the lateral thighs and dorsal trunk. Methods and materials Skin punch biopsy specimen were collected and analysed via routine histological examination and immunohistochemistry. After 14 weeks of oral ciclosporin treatment, repeat skin biopsy specimens were collected. Results Histopathological examination revealed noncaseating epithelioid cell granuloma formation in the dermis. Dermal epithelioid cells were positive for CD18 and Iba1, but not for CD3, CD20 and E‐cadherin based on immunohistochemistry findings. Acid‐fast bacteria, fungi and Leishmania spp. were not detected by special stains, culture or polymerase chain reaction. An initial two week treatment with immunosuppressive doses of oral prednisolone and doxycycline was not effective. Skin lesions were almost in remission after 14 weeks of oral ciclosporin treatment without adverse events. Histologically, the dermal granulomatous lesions regressed and were replaced by fibrous tissues after ciclosporin treatment. Conclusions and clinical relevance This case report describes the clinical and histopathological presentation including immunohistochemistry and treatment outcome of a case of canine sarcoidosis Ciclosporin may be an effective alternative to corticosteroids for treating canine sarcoidosis. Résumé Contexte La sarcoïdose est une dermatose granulomateuse caractérisée histologiquement par des granulomes nus chez de nombreux mammifères. La sarcoïdose canine est une maladie rare qui peut entrainer des papules et nodules non prurigineux sur le tronc, la face et les pavillons ; elle est habituellement traitée par des corticoïdes. A ce jour, il n'y a pas de cas publiés sur des traitements alternatifs aux corticoïdes. Objectifs Décrire un cas de sarcoïdose cutanée canine traitée avec succès par de la ciclosporine orale. Sujet Un chien beagle de 11 ans a été présenté avec des plaques pléomorphiques multiples sur les faces latérales et dorsale du tron