This review highlights recent key advances in the pathology and therapies of inflammatory skin diseases, focusing on atopic dermatitis (AD) and chronic spontaneous urticaria (CSU). Regarding AD, transcriptomic analysis with human samples revealed different immune profiles between childhood and adult AD. Phase III clinical trials of dupilumab, an anti–IL-4 receptor α antibody, in the treatment of AD have successfully finished, and dupilumab will appear in clinical practice as the first biologic for AD in 2017. In addition, a novel biologic that targets IL-31 shows promising results in a phase II trial. As for the skin microbiome study, novel insights into the mechanisms of microbial dysbiosis, such as colonization of Staphylococcus aureus, a common feature of AD, were proposed. Regarding CSU, autoreactive CD4+ T cells that react to FcεRI were discovered, which might contribute to the development of CSU. These findings provide new insights into the pathogenesis of AD and CSU and will lead to more specific and personalized treatments.