Itch has resisted many attempts to classify it as any one type of sensory experience. Pain and itch have very different behavioral response patterns. Itch generates stimulus of a foreign object underneath or upon the skin and also the fast hidradenitis suppurativa cure pdf free to remove it. For example, responding to a local itch sensation is an effective way to remove insects from one’s skin.
Scratching has traditionally been regarded as a way to relieve oneself by reducing the annoying itch sensation. It has been hypothesized that motivational aspects of scratching include the frontal brain areas of reward and decision making. These aspects might therefore contribute to the compulsive nature of itch and scratching. Even a discussion on the topic of itch can give one the desire to scratch. Itch is likely to be more than a localized phenomenon in the place we scratch. The sensation of pain can also be induced in a similar fashion, often by listening to a description of an injury, or viewing an injury itself.
The sensation of itch can be reduced by many painful sensations. Most are of an inflammatory nature. Mechano-responsive nociceptors have been shown in studies to respond to mostly pain, and mechano-insensitive receptors respond mostly to itch induced by histamine. Surgical removal of those skin layers removed the ability for a patient to perceive itch.
Sensitivity to pruritic stimuli is evenly distributed across the skin, and has a clear spot distribution with similar density to that of pain. Although experimentally induced itch can still be perceived under a complete A-fiber conduction block, it is significantly diminished. Overall, itch sensation is mediated by A-delta and C nociceptors located in the uppermost layer of the skin. NGF is high in injured or inflamed tissue.
P directly causes acute sensitization. A variety of over-the-counter and prescription anti-itch drugs are available. Some plant products have been found to be effective anti-pruritics, others not. Non-chemical remedies include cooling, warming, soft stimulation. Its mechanism of action remains unknown. Often, however, scratching can intensify itching and even cause further damage to the skin, dubbed the “itch-scratch-itch cycle.
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