Atopic Dermatitis (AD) is a prevalent inflammatory skin disease that is currently incurable. Plasma-treated solutions (PTS) (e.g., culture media, water, or normal saline, previously exposed to plasma) are being studied as novel therapy. Recently, PTS is gaining attention due to its advantages over non-thermal plasma (also known as cold atmospheric plasma). Thus, we explore the application of PTS in treating AD. In vivo experiments demonstrated that PTS significantly alleviated AD-like symptoms. It reduced mast cell and macrophage infiltration, decreased scratching times and serum IgE levels. These therapeutic effects of PTS on AD mice were associated with the activation of the antioxidant molecule Nrf2. In vitro experiments revealed that PTS could decrease ROS level and regulate cytokine expression (such as IL-6, IL-10, IL-13 and CCL17) in TNF-α/IFN-γ-stimulated keratinocytes and LPS-stimulated M1 macrophages. Additionally, PTS could upregulate the expression of antioxidant stress molecules such as Nrf2, HO-1, NQO1 and PPAR-γ in both cell types. Overall, PTS demonstrated potent therapeutic potential for AD without notable side effects. Our research provided a promising approach to AD treatment and may serve as a potential therapeutic strategy in other inflammatory skin diseases.