Currently, the principal strategy for immune checkpoint inhibitors (ICI)-related dermatitis include systemic use of corticosteroids, which can impair the efficacy of preceding ICIs treatment. Janus kinase inhibitors (JAKi) could be the optimal option for ICI-related dermatitis, which can not only provide rapid relief for ICI-related dermatitis but also potentially enhance the anti-tumor efficacy of ICIs with minimal adverse events. This is an open-lable, phase II trial, aims to evaluate efficacy and safety of JAK inhibitors for solid malignant tumor patients with refractory ICI-related dermatitis.