Cavalcanti Jacqueline V J, Hasbach Andrea, Barnes Katie, Dange Rahul B, Patterson Jon, Saavedra Paulo Vilar
Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 220 Trowbridge Road, East Lansing, MI, 48824, USA.
Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, 220 Trowbridge Road, East Lansing, MI, 48824, USA.
Vet Dermatol. 2017 Aug;28(4):400-e95. doi: 10.1111/vde.12422. Epub 2017 Feb 6.
Drug-induced depigmentation is frequently observed in humans undergoing tyrosine kinase inhibitor therapy, whereas it is not reported in dogs. The skin depigmentation can occur after the first week of treatment and it is reversible within a few weeks after drug discontinuation.
To report the clinical and histopathological features of an episode of cutaneous adverse drug reaction associated with short term administration of toceranib phosphate.
An 11-year-old intact male Bernese mountain dog was presented for investigation of a subcutaneous mast cell tumour (MCT) including treatment options. The major abnormality on physical examination was a 7.5 × 10 cm subcutaneous mass located cranial to the left shoulder joint consistent with a MCT. Toceranib phosphate therapy was initiated. Fourteen days after initiating treatment, the dog presented with skin erosions near the lateral canthus of the left eye. Three weeks later there were multiple skin lesions characterized by alopecia and depigmentation involving left and right eyelids; leukotrichia of the periorbital areas and depigmentation of the nasal planum and all paw pads. Histopathological findings were nonspecific; they were supportive of vitiligo. Resolution of skin lesions was observed after stopping the toceranib phosphate therapy.
Based on the gross lesions, histopathological features before and after tyrosine kinase inhibitor therapy, and Naranjo score, this case was considered to be consistent with cutaneous adverse drug effects. To the best of the authors' knowledge, this is the first report describing the clinical and histopathological features of presumed drug-induced skin depigmentation in a dog receiving toceranib phosphate.
在接受酪氨酸激酶抑制剂治疗的人类中经常观察到药物性色素脱失，而在犬类中未见报道。皮肤色素脱失可在治疗第一周后出现，停药后几周内可逆转。
报告与短期给予磷酸托西拉尼相关的皮肤药物不良反应事件的临床和组织病理学特征。
一只11岁未绝育的雄性伯恩山犬因皮下肥大细胞瘤（MCT）的检查及治疗方案前来就诊。体格检查的主要异常是位于左肩关节前方一个7.5×10厘米的皮下肿块，与MCT一致。开始给予磷酸托西拉尼治疗。治疗14天后，该犬左眼外眦附近出现皮肤糜烂。三周后，出现多处皮肤病变，特征为左、右眼睑脱毛和色素脱失；眶周区域白发病，鼻平面和所有爪垫色素脱失。组织病理学检查结果无特异性；支持白癜风。停用磷酸托西拉尼治疗后观察到皮肤病变消退。
根据大体病变、酪氨酸激酶抑制剂治疗前后的组织病理学特征以及纳兰霍评分，该病例被认为符合皮肤药物不良反应。据作者所知，这是第一份描述接受磷酸托西拉尼治疗的犬类中推测的药物性皮肤色素脱失的临床和组织病理学特征的报告。
