Pruritus is an individual unpleasant sensation of human sensory nervous system. In the physiological condition it excerts a self-protective mechanism to protect the skin against external harmful agents. Pruritoceptive itch is also a major symptom of skin diseases and a common reason for consulting a dermatologist in clinic. It has been well known that both histamine-dependent and histamine-inde...

Alopecia areata (AA) is commonly characterized by patchy areas of hair loss on the scalp. AA has been considered as a tissue-specific and T cell-mediated autoimmune disease of the hair follicles with a genetic predisposition to hair loss (1, 2). Patients with AA sometimes report experiencing itch on the scalp at the same time as an increase in hair loss activity. However, the relationship betwe...

Itch (pruritus) is one of the most often seen sensory phenomena in clinical practice. Recent neurophysiological findings proposed the existence of a novel pruriceptive system which includes a multitude of pruritogenic (itch-inducing) peripheral mediators, itch-selective pruriceptors, sensory afferent networks, spinal cord neurons, and certain central nervous system regions. In this review, we f...

Chronic itch could be a presenting sign of malignancy. Pruritus of lymphoma is the common prototype of paraneoplastic itch and can precede other clinical signs by weeks and months. Paraneoplastic pruritus has also been associated with solid tumors and is an important clinical symptom in paraneoplastic skin diseases such as erythroderma, Grovers disease, malignant acanthosis nigricans, generaliz...

Several studies show that itch and scratching cannot only be induced by pruritogens like histamine or cowhage, but also by the presentation of certain (audio-) visual stimuli like pictures on crawling insects or videos showing other people scratching. This phenomenon is coined "Contagious itch" (CI). Due to the fact that CI is more profound in patients with the chronic itchy skin disease atopic...

Dr Itch is evaluating a young man named Sam who has pruritic papules on his hands and genitals. A mineral oil preparation confirms scabies. Dr Itch recommends treatment with permethrin cream. Sam reveals that he lives with his girlfriend and brother, both of whom have developed symptoms suggestive of scabies. Neither Sam’s girlfriend nor his brother is a patient of Dr Itch. In fact, Sam confide...

Tachyphylaxis of itch refers to a markedly reduced scratching response to consecutive exposures of a pruritogen, a process thought to protect against tissue damage by incessant scratching and to become disrupted in chronic itch. Here, we report that a strong stimulation of the Mas-related G-protein-coupled receptor C11 by its agonist, Ser-Leu-Ile-Gly-Arg-Leu-NH2 (SL-NH2) or bovine adrenal medul...

Itch is a sensation that promotes the desire to scratch, which can be evoked by mechanical and chemical stimuli. In the spinal cord, neurons expressing the gastrin-releasing peptide receptor (GRPR) have been identified as specific mediators of itch. However, our understanding of the GRPR population in the spinal cord, and thus how these neurons exercise their functions, is limited. For this pur...

Recent findings suggest that itch produced by intradermal insertion of cowhage spicules in human is histamine independent. Neuronal mechanisms underlying nonhistaminergic itch are poorly understood. To investigate which nerve fibers mediate cowhage induced itch in man, action potentials were recorded from cutaneous C-fibers of the peroneal nerve in healthy volunteers using microneurography. Mec...

This study investigated sex-specific differences in itch perception and skin reactions, as modulated by verbal suggestions, and the role of the investigator's sex. Healthy volunteers (50 males, 50 females), divided into 4 groups, were tested by male and female investigators. Itch was induced via prick testing with sodium chloride and histamine in 4 runs; 2 control conditions (with no exaggerate...