Preclinical and human surrogate models of itch

Pruritus, or simply itch, is a debilitating symptom that significantly decreases the quality of life in a wide range of clinical conditions. While histamine remains the most studied mediator of itch in humans, treatment options for chronic itch, in particular antihistamine-resistant itch, are limited. Relevant preclinical and human surrogate models of non-histaminergic itch are needed to accelerate the development of novel antipruritics and diagnostic tools. Advances in basic itch research have facilitated the development of diverse models of itch and associated dysaesthesiae. While experimental itch in humans is induced over a short period of time and usually assessed psychophysically, the study of itch reactions in animals allows for both short-term and long-term studies but relies heavily on behavioural assessments. This review provides a background and a presentation of the established models of itch currently applied in animals and humans with emphasis on translatability.