What makes skin 'itch'?
I know dry skin and all will do that, but what precisely happens to those skin cells that make them react so that they need relief?? And why does the act of scratching, give those cells relief? does the scratch release some type of phermone that satisfies the other cells??????
- yachadhooLv 61 decade agoFavorite Answer
One suspected mechanism is that there are specialized nerves that transmit a signal to the brain, much in the same way pain is sensed. Slight hair movement (or other stimulus) on the surface of the skin triggers receptors on nerve endings that transmit a signal to the brain giving a sensation of "itch". Other similar, but different receptors transmit pain...or light touch...or cold/hot.
Another mechanism is that there are specialized cells called mast cells that hang out in the skin fighting off pathogens or other things that may harm the body (or things they THINK will harm the body, but don't...such as allergens that cause allergies in some people). When the pathogen or allergen tries to get into the body and invade, the mast cells attack and release a chemical called histamine. This chemical, histamine, attaches to receptors on a specialized tract in the nervous system (like pain, light touch, hot/cold sensations) that transmit a sensation of "itch" to the brain.
Scratching an itch in itself is not thought to "satisfy" the cells, but only to prompt the person to get rid of the offending agent...in a protective way. If there was something attacking the body (a bug, say) and hairs triggered an itch, then scratching might get rid of the offending agent.
Although, there possibly is some sort of feedback inhibition that stops the itch, I don't know. And I don't know if anybody knows if this is true, but it certainly seems reasonable and consistent with most human physiology.
Ironically, scratching an itch can actually cause more itching! Especially when related to histamine released by mast cells in response to an allergen. The scratch could potentially disrupt the skin and cause more allergen to infiltrate...and more mast cells to attack and release more histamine...and the sensation of "itch" gets worse! This often happens in poison ivy. At first, the poison is just at one tiny spot. But then, the person itches, and the poison spread on/in the body...and the rash (and itch) gets a lot worse!
In any event, that is why a doctor often gives an "anti-histamine" in a allergic reaction (like Benadryl). This blocks the histamine from tripping "itch" receptors, giving some itch relief. It also calms down a bodily reaction to something perceived as dangerous to the body, that really is not dangerous to the body (an overactive immune system, which is really what allergies are).
In any event, there is a lot that is still not fully understood regarding the sensation of itch...(and a lot more that I don't know).
But, nobody else had answered your question...so I thought I'd give it my best.
Hope you got something out of it.
- Anonymous5 years ago
Proactive nor any other acne medication out there is supposed to irritate your skin. If your check the label on most of the acne products they tell you to discontine use if it is irritating and/or drying out your skin. For the moment i would use a product that is geared towards sensitive skin. Finally, generic brands,no matter how much they "claim" to be as good as the original,are never as good as the original product. Sometime you just have to pay a little extra to get a quality product.