Protease-activated receptors (PARs) have been implicated in a variety of physiological functions, as well as somatosensation and particularly itch and pain. Considerable attention has focused on PARs following the finding they are upregulated in the skin of atopic dermatitis patients. The present review focuses on recent studies showing that PARs are critically involved in itch and sensitizatio...

Background: Pruritus Ani (PA) is the chronic itch of perianal skin and is poorly understood. There is a knowledge gap in understanding the pathophysiology and management of PA as there has been little research. The literature is sparse and of variable quality. There have been recent studies in understanding pruritic processing. We have performed a critical review of the literature concerning th...

Itch, or pruritus, is an important clinical problem whose molecular basis has yet to be understood. Recent work has begun to identify genes that contribute to detecting itch at the molecular level. Here we show that Pirt, known to play a vital part in sensing pain through modulation of the transient receptor potential vanilloid 1 (TRPV1) channel, is also necessary for proper itch sensation. Pir...

Opioids such as morphine numb pain but often concomitantly induce itch. Liu et al. (2011) now separate the sensation of itch from opioid-induced analgesia, showing that in a subset of spinal neurons, morphine directly induces itch by signaling through a heteromer of opioid- and itch-mediating G protein-coupled receptors.

Despite its clinical importance, the underlying neural mechanisms of itch sensation are poorly understood. In many diseases, pruritus is not effectively treated with antihistamines, indicating the involvement of nonhistaminergic mechanisms. To investigate the role of small myelinated afferents in nonhistaminergic itch, we tested, in psychophysical studies in humans, the effect of a differential...

Lichen planus (LP) skin lesions are often accompanied by itch, but this symptom has not been thoroughly examined in LP. To better characterize itch in LP, 78 patients with LP were investigated. Itch was present in 94.9% of patients and was usually described as the most vexing symptom of LP. The mean?±?SD severity of itch according to visual analogue scale score was 6.9?±?2.8 points. Most patien...

Itch is described as an unpleasant sensation that elicits the desire to scratch, which results in the removal of the irritant from the skin. The cough reflex also results from irritation, with the purpose of removing said irritant from the airway. Could cough then be similar to itch? Anatomically, both pathways are mediated by small-diameter sensory fibers. These cough and itch sensory fibers r...

All humans experience itch in the course of their life. Even a discussion on the topic of itch or seeing people scratch can evoke the desire to scratch. These events are coined "contagious itch" and are very common. We and others have shown that videos showing people scratching and pictures of affected skin or insects can induce itch in healthy persons and chronic itch patients. In our studies,...

Itch is a major somatic sensation, along with pain, temperature, and touch, detected and relayed by the somatosensory system. Itch can be an acute sensation, associated with mosquito bite, or a chronic condition, like atopic dermatitis (29, 59). The origins of the stimulus can be localized in the periphery or systemic, and associated with organ failure or cancer. Itch is also a perception origi...

IL-31 receptor blockade suppresses pruritus of atopic dermatitis. However, cell type-specific contributions to itch, its expression mechanism, and the downstream signaling pathway induce itch remain unknown. Here, using conditional knockout mice, we demonstrated that IL-31-induced required sensory neuronal STAT3. was decreased in STAT3 deficient indicating dependent on neurons. In addition, an ...