The today and tomorrow of (almost) each itch

Itch is an unpleasant sensation on the skin that causes the desire to scratch. Its aetiology can be defined by various categories such as cause, period of occurrence, location, and the presence or absence of skin disease in a given area. This burdensome symptom experience can even be compared to chronic pain in terms of quality-of-life-impairment and is particularly common among older people. This article discusses the neural pathways that cause itch, the important but clinically challenging role of histamine, and some of the mechanisms involved in the itch-scratch cycle, such as some quite novel discoveries regarding the contributions of the gastrin-releasing peptide (GRP)/ /gastrin-releasing peptide receptor (GRPR) axis, transient receptor potential (TRP) channels, and Janus kinase. Pruritus may be associated with various types of diseases affecting the maternal-foetal relationship, skin, cholestasis, renal system or mental health. Some new therapeutic options include drugs that affect opioid receptors, neurokinin 1 receptor (NK-1R) antagonists, Janus kinase inhibitors, and biologics made by combining antibodies against different types of interleukins associated with the itch sensation. Nevertheless, finding an effective form of therapy for patients with various underlying conditions remains a challenge and is the subject of ongoing clinical research.