Significance Wireless electronics for monitoring of skin hydration in a quantitative fashion have broad relevance to our understanding of dermatological health and skin structure in both clinical and home settings. Here, we present a miniaturized, long-range automated system that adheres gently to the skin to yield quantitative recordings of skin water content for both epidermis and dermis. This system supports capabilities in characterizing skin barrier, assessing severity of skin diseases, and evaluating cosmetic and medication efficacy, with high levels of repeatability and insensitivity to ambient. Benchtop and pilot studies on patients with skin diseases highlight key features of these devices and their potential for broad utility in clinical research and in home settings to guide the management of disorders of the skin.