New Definitions and Subtypes of Chronic Prurigo.

Over the past few years, chronic prurigo, including prurigo nodularis, has become a focal point of considerable research attention, resulting in enhanced insights into this condition. For over two centuries, the term "prurigo" has been utilized in dermatology, often applied loosely to describe a range of pruritic, papulous conditions lacking clear diagnostic criteria. In 2017, the term "chronic prurigo" was introduced, delineating chronic prurigo including prurigo nodularis as a distinct disease entity characterized by chronic pruritus, a characteristic clinical history, and physical signs such as excoriations and the presence of pruriginous lesions. Pruriginous lesions exhibit diverse morphologies, encompassing papules (diameter < 1 cm), nodules (diameter > 1 cm), plaques, and umbilicated or linear lesions. Co-occurrence of multiple lesion types within an individual is frequently observed. The subtype and severity of chronic prurigo can be categorised on the basis of the type or number of pruriginous lesions.