How Frequent Is Itch? Facts and Thoughts of a Long Neglected Aspect of Itch

Itch is the most frequent symptom of the skin, but its epidemiology including frequency has not been researched until a few years ago. Data is limited due to, e.g., the undulatory pattern of this symptom and the wide clinical spectrum such as itch being associated with a skin disease and itch on normal-looking skin. In addition, itch is an interdisciplinary symptom that is not paid attention to the same way in all clinical disciplines. This diversity may explain the incompleteness of epidemiological data of itch. With a recurrent symptom, it is important to consider different prevalence estimates (point-, 12-month, and lifetime prevalence) and to have a clear definition of itch. Recent population-based research demonstrates that more people suffer from chronic itch than previously assumed. The chapter summarizes new findings concerning the epidemiology of itch in the general population and in selected patient populations.