Women Skin Treatment

Activation of brain areas previously linked to addiction and the formation of strong emotional attachments appears to "underline the hedonistic aspects of scratching," Alexandra D. Papaya, MD, PhD, of Wake Forest University in Winston-Salem, N.C., and colleagues reported in a poster presentation.

"These findings highlight the addictive nature of the itch-scratch cycle and suggest a role for the dopaminergic system in the central nervous system in modulating itch relief. Functional imaging studies in relation to purities could be further designed to develop an effective therapy in the future," they added.

Previous studies of brain processing related to the itch-scratch cycle involved interventions that mimicked scratching. Real scratching constitutes a conscious, voluntary, motor response that is continuously adjusted by means of a neural feedback system, Papaya and colleagues noted. Feedback loops assess receptive inputs and "appreciate the reward" afforded by scratching.

For active scratching the volunteers were instructed to use only the tips of their fingers and to try to avoid all other movement. Passive scratching was performed by observers using a cytology brush.

The results showed that higher baseline itch was associated with increased itch reduction by scratching at all three sites. For the forearm and ankle, higher itch during scratching correlated with increased pleasurably.