The management of rheumatoid arthritis (RA) requires long-term monitoring and dynamic adjustment of treatment over time. Yu Liu et al. now present in Science Advances a wearable electronic device that might enable real-time disease monitoring and adjustable drug delivery.

Electrical impedance of tissues is altered following changes in tissue integrity and cellular distribution, as it is influenced, for example, by accumulation of interstitial fluid and infiltration by inflammatory cells. Liu et al. showed in a rat model of adjuvant-induced arthritis that changes in skin impedance correlated with local inflammation. The authors also built a preliminary machine learning model to assess disease activity on the basis of transdermal impedance.