Interesting Facts About Itch: Sensory And Self-Protective Mechanism

Having an itch can be incredibly annoying but it actually serves an important function, protecting us from damage to our skin. However, scientists have long struggled to explain what actually causes the sensation – in particular why some types of touch cause an itch whereas others do not.
Now a new study in mice has shed light on what actually happens in the body when we want to scratch an itch. The research, published in Science, could lead to treatments for many thousands of people suffering from chronic itch, a disorder causing an intense desire to scratch.
An itch, also known as pruritus, is a general sensation arising from the irritation of skin cells or nerve cells associated with the skin. While it can be a nuisance, pruritus serves as an important sensory and self-protective mechanism, as do other skin sensations such as touch, pain, vibration, cold and heat. It can alert us to harmful external agents, but can become unbearable if not treated.
Pruritus is a dominant symptom of many skin diseases and also occurs in some diseases that affect the entire body. An itching sensation of the skin arises due to stimulation of pruriceptors—itch-sensing nerve endings—by mechanical, thermal or chemical mediators.
Below are some interesting facts about Itch:
1. One of the worst culprits of itching is dermatitis, a skin condition caused by anything from laundry detergent to gold that can irritate the skin. In the United States, 6.4 million people with dermatitis scratch their way to the dermatologist’s office each year, according to a National Ambulatory Medical Care Survey.
2. Histamine, a protein released during an allergic reaction, commands some of our itch nerves to transmit information to the spinal cord where it is processed and zipped off to the brain. The sites activated in the brain when we itch are very similar to those switched on when we’re in pain. Antihistamine drugs work by disabling the protein’s signaling powers.
3. Fibers sensitive to itch were first discovered almost a decade ago by Schmelz. Recently, he’s found the existence of new fibers that stimulate itchy feelings in a different way than the histamine-sensitive nerves he previously identified.
4. In 1660, Samuel Hafenreffer proposed the first definition of the itching symptom, as “an unpleasant desire to scratch.”
Scratching the skin serves as a quick fix or may just add to one’s misery. Severe clawing can even cause bleeding and infection.
5. Despite approximately a century of pruritus research, there is no single effective antipruritic treatment, but several topical and orally-administered agents are available that suppress itching in certain clinical settings. These agents include lotions and creams (such as calamine and hydrocortisone), antihistamines, opioid antagonists, aspirin and ultraviolet light therapy.
6. The itching sensation usually occurs following a light touch on the hairy skin of our bodies. This triggers us to move our hand to the source of the insult and scratch away at it. While seemingly mindless, this simple behavior is our body’s neat way of attempting to protect us from damage to our skin from objects in the environment or nasty insects and parasites.
7. Surprisingly, there is some evidence to suggest it is not only occurrences on your skin that can cause itch and there may be a psychological element. Reports of contagious itching where watching others scratch can cause a person to feel an itch are widespread. Indeed, a recent study showed that visual and auditory scratch-related stimuli during a lecture caused a significant increase in scratching behavior in the audience.

Leave a Reply, No Login Necessary.