Intense itch and urge to scratch are the major symptoms of many chronic skin ailments, which are increasingly common. Vicious itch-scratch cycles are readily established and may diminish quality of life for those afflicted. We investigated peripheral and central processing of two types of itch sensation elicited by skin-prick tests of histamine and allergen solutions. Itch-related skin blood fl...

1 Intense itch and urge to scratch are the major symptoms of many chronic skin ailments, which are increasingly common. Vicious itch-scratch cycles are readily established and may diminish quality of life for those afflicted. We investigated peripheral and central processing of two types of itch sensation, elicited by skin prick tests of histamine and allergen solutions. Itch-related skin blood...

Physical complaints, such as pain, can be effectively reduced by placebo effects through induction of positive expectations, or increased by nocebo effects through induction of negative expectations. In the present study, verbally induced nocebo and placebo effects on itch were experimentally investigated for the first time. In part 1, the role of verbal suggestions in inducing nocebo effects o...

Itch is an aversive sensory experience and while systemic therapies, such as acupuncture, have shown promise in alleviating itch in patients suffering from chronic itch, their antipruritic mechanisms are unknown. As several lines of evidence implicate brain-focused mechanisms, we applied functional magnetic resonance imaging and our validated temperature-modulation itch model to evaluate the un...

Background Post-herpetic itch (PHI) is a neuropathic itch syndrome following herpes zoster. It has been reported that PHI is occasionally sufficiently severe to compromise patients' quality of life and frequently refractory to treatment. Here, we present a case of severe chronic PHI successfully treated with supraorbital nerve block using a high concentration of tetracaine dissolved in bupivaca...

The neuronal pathways for itch have been characterized mainly based on responses to histamine. Intracutaneous application of histamine produces intense itch and a large area of axon-reflexive vasodilation ("flare") around the application site. Both phenomena are thought to be mediated through neuronal activity in itch-specific, mechanoinsensitive C-fiber afferents (CMi). However, mechanical and...

BACKGROUND Even though itch is a common syndrome of many diseases there is only little knowledge about sex and gender differences in pruritus, especially in central itch perception and modulation. To our knowledge, this is the first fMRI study examining sex differences in perception and its modulation by distraction. METHODS Experimental itch was induced by application of histamine (0.1 mM) v...

Itch is one of the major complications of skin diseases. Although there are various substances that induce itch or pruritus, it is evident that histamine is the best known endogenous agent that evokes itch. Even though histamine-induced itch has been studied for some time, the underlying mechanism of itch is just beginning to emerge. Although various downstream signaling pathways of histamine r...

A substantial proportion of patients with burn injury develop chronic itch, which can severely affect their quality of life. As found in research on chronic pain, different psychophysiological processes may also play a role in chronic itch, of which central sensitization, conditioned modulation, and attentional processes have been studied most frequently. This study aimed to explore psychophysi...

BACKGROUND Psychological factors are known to significantly modulate itch in patients suffering from chronic itch. Itch is also highly susceptible to both placebo and nocebo (negative placebo) effects. Brain activity likely supports nocebo-induced itch, but is currently unknown. METHODS We collected functional MRI (fMRI) data from atopic dermatitis (AD) patients, in a within-subject design, a...