Bae S, Yu J, Jeong H, Oh T
Department of Veterinary Internal Medicine, College of Veterinary Medicine, Kyunpook National University, Daegu 41566, Republic of Korea.
Pol J Vet Sci. 2018 Dec;21(4):789-796. doi: 10.24425/pjvs.2018.125599.
Several human studies have reported that capsaicin has anti-pruritic effects. Moreover, sever- al concentrations of topical capsaicin have been used to alleviate itch. The aim of this study was to investigate the anti-pruritic effect of capsaicin against histamine-induced pruritus compared with that of topical steroid or vehicle in 15 healthy beagles. Fifteen dogs were divided into three groups (n = 5 each), and treated topically with one of the following on the left side of the neck: capsaicin, positive control (steroid), or negative control (vehicle). Each treatment was performed twice daily for 8 days. All dogs were injected with histamine intradermally before treatment and on the 2nd, 4th, 6th, and 8th days of the treatment to evoke itch. Pruritus, wheal, and erythema intensity were assessed at each evaluation; cutaneous temperature was also recorded. On the final day, skin biopsy was conducted for histopathological evaluation for all dogs. The severity of pruritus was lesser in the capsaicin-treated group compared with the negative control group on day 8 (p⟨0.05). In the capsaicin and steroid groups, wheal size, erythema index, and cutaneous temperature also decreased compared with pretreatment. Histopathological evaluation showed that the capsaicin-treated group had a higher number of inflammatory cells in the dermis com- pared to the vehicle control group; however, the steroid-treated group showed less severe inflam- matory reactions than the vehicle control group. These results suggest that capsaicin cannot reduce inflammation but may play a helpful role in reducing pruritus in dogs.
多项人体研究报告称辣椒素具有止痒作用。此外，几种浓度的外用辣椒素已被用于缓解瘙痒。本研究的目的是在15只健康的比格犬中，研究辣椒素与外用类固醇或赋形剂相比对组胺诱导的瘙痒的止痒效果。15只狗被分成三组（每组n = 5），并在颈部左侧局部使用以下其中一种进行治疗：辣椒素、阳性对照（类固醇）或阴性对照（赋形剂）。每种治疗每天进行两次，持续8天。所有狗在治疗前以及治疗的第2、4、6和8天进行皮内注射组胺以诱发瘙痒。在每次评估时评估瘙痒、风团和红斑强度；还记录皮肤温度。在最后一天，对所有狗进行皮肤活检以进行组织病理学评估。在第8天，与阴性对照组相比，辣椒素治疗组的瘙痒严重程度较轻（p⟨0.05）。与治疗前相比，辣椒素组和类固醇组的风团大小、红斑指数和皮肤温度也有所下降。组织病理学评估显示，与赋形剂对照组相比，辣椒素治疗组真皮中的炎症细胞数量更多；然而，类固醇治疗组的炎症反应比赋形剂对照组轻。这些结果表明，辣椒素不能减轻炎症，但可能在减轻犬类瘙痒方面发挥有益作用。
