Pruritus, Prurigo and Lichen Simplex

Abstract

Abstract Chronic pruritus is a common, complex dermatological symptom that has a profound impact on patients and society. It is highly prevelant in the majority of inflammatory skin diseases as well as in bullous autoimmune dermatoses, cutaneous lymphoma, cutaneous drug reactions and ageing skin. Chronic pruritus is also common in non‐dermatological diseases such as advanced stages of chronic kidney disease, hepatobiliary diseases and lymphoproliferative disorders, as well as neuropathies and disorders with psychogenic causes. The pathophysiology is complex and involves many itch mediators and receptors that differ between the diseases, with common neuronal pathways. The majority of types of chronic itch are transmitted by non‐histamnergic nerve fibres. In many inflammatory skin diseases a cross‐talk exists between keratinocytes, the immune system and sensory nerves. The pruritus characteristics of itch and therapy targets may differ between the different aetiological entities, but the impact on quality of life, sleep and psychosocial burden is common to all patients.